Patent Application
20250204144
The present disclosure generally relates to novel device architectures and the OLED devices having those novel architectures and their uses.
Opto-electronic devices that make use of organic materials are becoming increasingly desirable for various reasons. Many of the materials used to make such devices are relatively inexpensive, so organic opto-electronic devices have the potential for cost advantages over inorganic devices. In addition, the inherent properties of organic materials, such as their flexibility, may make them well suited for particular applications such as fabrication on a flexible substrate. Examples of organic opto-electronic devices include organic light emitting diodes/devices (OLEDs), organic phototransistors, organic photovoltaic cells, organic scintillators, and organic photodetectors. For OLEDs, the organic materials may have performance advantages over conventional materials.
OLEDs make use of thin organic films that emit light when voltage is applied across the device. OLEDs are becoming an increasingly interesting technology for use in applications such as displays, illumination, and backlighting.
One application for emissive molecules is a full color display. Industry standards for such a display call for pixels adapted to emit particular colors, referred to as “saturated” colors. In particular, these standards call for saturated red, green, and blue pixels. Alternatively, the OLED can be designed to emit white light. In conventional liquid crystal displays emission from a white backlight is filtered using absorption filters to produce red, green and blue emission. The same technique can also be used with OLEDs. The white OLED can be either a single emissive layer (EML) device or a stack structure. Color may be measured using CIE coordinates, which are well known to the art.
In one aspect, the present disclosure provides a pixel arrangement of a device comprising at least one pixel wherein the at least one pixel comprises: a first subpixel comprising a first OLED (1) comprising an emissive region ER11; a second subpixel comprising a second OLED (2) comprising an emissive region ER21; wherein the ER11 comprises: a compound S1; and a compound A1; wherein the ER21 comprises: a compound S2; and a compound A2; wherein the compound S1 is a sensitizer that transfers energy to the compound A1; and the compound S2 is a sensitizer that transfers energy to the compound A2; wherein each of the compound A1 and A2 is independently an acceptor that is an emitter; wherein the compound S1 can be same or different from the compound S2; and wherein the compound A1 can be same or different from the compound A2.
In another aspect, the present disclosure also provides an organic light emitting device (OLED (5)) comprising: an anode; an emissive region ER11′ and an emissive region ER21′ disposed over the anode and separated by a charge generation layer (CGL); and a cathode disposed over the ER11′ and ER21′; wherein the ER11′ comprises: a compound S1′; and a compound A1′; wherein the ER21′ comprises: a compound S2′; and a compound A2′; wherein the compound S1′ is a sensitizer that transfers energy to the compound A1′; and the compound S2′ is a sensitizer that transfers energy to the compound A2′; wherein each of the compounds A1′ and A2′ is independently an acceptor that is an emitter; wherein the compound S1′ can be same or different from the compound S2′; and wherein the compound A1′ can be same or different from the compound A2′.
In yet another aspect, the present disclosure further provides a consumer product comprising a pixel arrangement or an OLED (5) as described herein.
Unless otherwise specified, the below terms used herein are defined as follows:
As used herein, “top” means furthest away from the substrate, while “bottom” means closest to the substrate. Where a first layer is described as “disposed over” a second layer, the first layer is disposed further away from substrate. There may be other layers between the first and second layer, unless it is specified that the first layer is “in contact with” the second layer. For example, a cathode may be described as “disposed over” an anode, even though there are various organic layers in between.
As used herein, “solution processable” means capable of being dissolved, dispersed, or transported in and/or deposited from a liquid medium, either in solution or suspension form.
As used herein, and as would be generally understood by one skilled in the art, a first “Highest Occupied Molecular Orbital” (HOMO) or “Lowest Unoccupied Molecular Orbital” (LUMO) energy level is “greater than” or “higher than” a second HOMO or LUMO energy level if the first energy level is closer to the vacuum energy level. Since ionization potentials (IP) are measured as a negative energy relative to a vacuum level, a higher HOMO energy level corresponds to an IP having a smaller absolute value (an IP that is less negative). Similarly, a higher LUMO energy level corresponds to an electron affinity (EA) having a smaller absolute value (an EA that is less negative). On a conventional energy level diagram, with the vacuum level at the top, the LUMO energy level of a material is higher than the HOMO energy level of the same material. A “higher” HOMO or LUMO energy level appears closer to the top of such a diagram than a “lower” HOMO or LUMO energy level.
As used herein, and as would be generally understood by one skilled in the art, a first work function is “greater than” or “higher than” a second work function if the first work function has a higher absolute value. Because work functions are generally measured as negative numbers relative to vacuum level, this means that a “higher” work function is more negative. On a conventional energy level diagram, with the vacuum level at the top, a “higher” work function is illustrated as further away from the vacuum level in the downward direction. Thus, the definitions of HOMO and LUMO energy levels follow a different convention than work functions.
The terms “halo,” “halogen,” and “halide” are used interchangeably and refer to fluorine, chlorine, bromine, and iodine.
The term “acyl” refers to a substituted carbonyl group (—C(O)—Rs).
The term “ester” refers to a substituted oxycarbonyl (—O—C(O)—Rs, or —C(O)—O—Rs) group.
The term “ether” refers to an —ORs group.
The terms “sulfanyl” or “thio-ether” are used interchangeably and refer to a —SRs group.
The term “selenyl” refers to a —SeRs group.
The term “sulfinyl” refers to a —S(O)—Rs group.
The term “sulfonyl” refers to a —SO2—Rs group.
The term “phosphino” refers to a group containing at least one phosphorus atom bonded to the relevant structure. Common examples of phosphino groups include, but are not limited to, groups such as a —P(Rs)2 group or a —PO(Rs)2 group, wherein each Rs can be same or different.
The term “silyl” refers to a group containing at least one silicon atom bonded to the relevant structure. Common examples of silyl groups include, but are not limited to, groups such as a —Si(Rs)3 group, wherein each Rs can be same or different.
The term “germyl” refers to a group containing at least one germanium atom bonded to the relevant structure. Common examples of germyl groups include, but are not limited to, groups such as a —Ge(Rs)3 group, wherein each Rs can be same or different.
The term “boryl” refers to a group containing at least one boron atom bonded to the relevant structure. Common examples of boryl groups include, but are not limited to, groups such as a —B(Rs)2 group or its Lewis adduct —B(Rs)3 group, wherein Rs can be same or different.
In each of the above, Rs can be hydrogen or a substituent selected from the group consisting of the General Substituents as defined in this application. Preferred Rs is selected from the group consisting of deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, and combination thereof. More preferably Rs is selected from the group consisting of alkyl, cycloalkyl, aryl, heteroaryl, and combination thereof.
The term “alkyl” refers to and includes both straight and branched chain alkyl groups having an alkyl carbon atom bonded to the relevant structure. Preferred alkyl groups are those containing from one to fifteen carbon atoms, preferably one to nine carbon atoms, and includes methyl, ethyl, n-propyl, iso-propyl, n-butyl, sec-butyl, iso-butyl, tert-butyl, n-pentyl, 2-methylbutyl, 3-methylbutyl, 2,2-dimethylpropyl, 1,3-dimethylpropyl, 1,1-dimethylpropyl, 2-ethylpropyl, 1,2-dimethylpropyl, n-hexyl, 2-methylpentyl, 3-methylpentyl, 2,2-dimethylbutyl, 2,3-dimethylbutyl, n-heptyl, 2-methylhexyl, 3-methylhexyl, 2,2-dimethylpentyl, 2,3-dimethylpentyl, 2,4-dimethylpentyl, 3,3-dimethylpentyl, 3-ethylpentyl, 2,2,3-trimethylbutyl, and the like. Additionally, the alkyl group can be further substituted.
The term “cycloalkyl” refers to and includes monocyclic, polycyclic, and spiro alkyl groups having a ring alkyl carbon atom bonded to the relevant structure. Preferred cycloalkyl groups are those containing 3 to 12 ring carbon atoms and includes cyclopropyl, cyclopentyl, cyclohexyl, bicyclo[3.1.1]heptyl, spiro[4.5]decyl, spiro[5.5]undecyl, adamantyl, and the like. Additionally, the cycloalkyl group can be further substituted.
The terms “heteroalkyl” or “heterocycloalkyl” refer to an alkyl or a cycloalkyl group, respectively, having at least one carbon atom replaced by a heteroatom. Optionally the at least one heteroatom is selected from O, S, N, P, B, Si, Ge and Se, preferably, O, S or N. Additionally, the heteroalkyl or heterocycloalkyl group can be further substituted.
The term “alkenyl” refers to and includes both straight and branched chain alkene groups. Alkenyl groups are essentially alkyl groups that include at least one carbon-carbon double bond in the alkyl chain with one carbon atom from the carbon-carbon double bond that is bonded to the relevant structure. Cycloalkenyl groups are essentially cycloalkyl groups that include at least one carbon-carbon double bond in the cycloalkyl ring. The term “heteroalkenyl” as used herein refers to an alkenyl group having at least one carbon atom replaced by a heteroatom. Optionally the at least one heteroatom is selected from O, S, N, P, B, Si, Ge, and Se, preferably, O, S, or N. Preferred alkenyl, cycloalkenyl, or heteroalkenyl groups are those containing two to fifteen carbon atoms. Additionally, the alkenyl, cycloalkenyl, or heteroalkenyl group can be further substituted.
The term “alkynyl” refers to and includes both straight and branched chain alkyne groups. Alkynyl groups are essentially alkyl groups that include at least one carbon-carbon triple bond in the alkyl chain with one carbon atom from the carbon-carbon triple bond that is bonded to the relevant structure. Preferred alkynyl groups are those containing two to fifteen carbon atoms. Additionally, the alkynyl group can be further substituted.
The terms “aralkyl” or “arylalkyl” are used interchangeably and refer to an aryl-substituted alkyl group having an alkyl carbon atom bonded to the relevant structure. Additionally, the aralkyl group can be further substituted.
The term “heterocyclic group” refers to and includes aromatic and non-aromatic cyclic groups containing at least one heteroatom. Optionally the at least one heteroatom is selected from O, S, Se, N, P, B, Si, Ge, and Se, preferably, O, S, N, or B. Hetero-aromatic cyclic groups may be used interchangeably with heteroaryl. Preferred hetero-non-aromatic cyclic groups are those containing 3 to 10 ring atoms, preferably those containing 3 to 7 ring atoms, which includes at least one hetero atom, and includes cyclic amines such as morpholino, piperidino, pyrrolidino, and the like, and cyclic ethers/thio-ethers, such as tetrahydrofuran, tetrahydropyran, tetrahydrothiophene, and the like. Additionally, the heterocyclic group can be further substituted or fused.
The term “aryl” refers to and includes both single-ring and polycyclic aromatic hydrocarbyl groups. The polycyclic rings may have two or more rings in which two carbons are common to two adjoining rings (the rings are “fused”). Preferred aryl groups are those containing six to thirty carbon atoms, preferably six to twenty-four carbon atoms, six to eighteen carbon atoms, and more preferably six to twelve carbon atoms. Especially preferred is an aryl group having six carbons, ten carbons, twelve carbons, fourteen carbons, or eighteen carbons. Suitable aryl groups include phenyl, biphenyl, triphenyl, triphenylene, tetraphenylene, naphthalene, anthracene, phenalene, phenanthrene, pyrene, chrysene, perylene, and azulene, preferably phenyl, biphenyl, triphenyl, triphenylene, and naphthalene. Additionally, the aryl group can be further substituted or fused, such as, without limitation, fluorene.
The term “heteroaryl” refers to and includes both single-ring aromatic groups and polycyclic aromatic ring systems that include at least one heteroatom. The heteroatoms include, but are not limited to O, S, Se, N, P, B, Si, Ge, and Se. In many instances, O, S, N, or B are the preferred heteroatoms. Hetero-single ring aromatic systems are preferably single rings with 5 or 6 ring atoms, and the ring can have from one to six heteroatoms. The hetero-polycyclic ring systems can have two or more aromatic rings in which two atoms are common to two adjoining rings (the rings are “fused”) wherein at least one of the rings is a heteroaryl. The hetero-polycyclic aromatic ring systems can have from one to six heteroatoms per ring of the polycyclic aromatic ring system. Preferred heteroaryl groups are those containing three to thirty carbon atoms, preferably three to twenty-four carbon atoms, three to eighteen carbon atoms, and more preferably three to twelve carbon atoms. Suitable heteroaryl groups include dibenzothiophene, dibenzofuran, dibenzoselenophene, furan, thiophene, benzofuran, benzothiophene, benzoselenophene, carbazole, indolocarbazole, pyridylindole, pyrrolodipyridine, pyrazole, imidazole, triazole, oxazole, thiazole, oxadiazole, oxatriazole, dioxazole, thiadiazole, pyridine, pyridazine, pyrimidine, pyrazine, triazine, oxazine, oxathiazine, oxadiazine, indole, benzimidazole, indazole, indoxazine, benzoxazole, benzisoxazole, benzothiazole, quinoline, isoquinoline, cinnoline, quinazoline, quinoxaline, naphthyridine, phthalazine, pteridine, xanthene, acridine, phenazine, phenothiazine, phenoxazine, benzofuropyridine, furodipyridine, benzothienopyridine, thienodipyridine, benzoselenophenopyridine, selenophenodipyridine, azaborine, borazine, 5λ2,9λ2-diaza-13b-boranaphtho[2,3,4-de]anthracene, 52′-benzo[d]benzo[4,5]imidazo[3,2-a]imidazole, and 5,9-dioxa-13b-boranaphtho[3,2,1-de]anthracene; preferably dibenzothiophene, dibenzofuran, dibenzoselenophene, carbazole, indolocarbazole, imidazole, pyridine, triazine, benzimidazole, 5λ2,9λ2-diaza-13b-boranaphtho[2,3,4-de]anthracene, 5λ2-benzo[d]benzo[4,5]imidazo[3,2-a]imidazole, and 5,9-dioxa-13b-boranaphtho[3,2,1-de]anthracene. Additionally, the heteroaryl group can be further substituted or fused.
Of the aryl and heteroaryl groups listed above, the groups of triphenylene, naphthalene, anthracene, dibenzothiophene, dibenzofuran, dibenzoselenophene, carbazole, indolocarbazole, imidazole, pyridine, pyrazine, pyrimidine, triazine, benzimidazole, 5λ2,9λ2-diaza-13b-boranaphtho[2,3,4-de]anthracene, 5λ2-benzo[d]benzo[4,5]imidazo[3,2-a]imidazole, 5,9-dioxa-13b-boranaphtho[3,2,1-de]anthracene, and the respective aza-analogs of each thereof are of particular interest.
In many instances, the General Substituents are selected from the group consisting of deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, germyl, boryl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carboxylic acid, ether, ester, nitrile, isonitrile, sulfanyl, selenyl, sulfinyl, sulfonyl, phosphino, and combinations thereof.
In some instances, the Preferred General Substituents are selected from the group consisting of deuterium, fluorine, alkyl, cycloalkyl, heteroalkyl, alkoxy, aryloxy, amino, silyl, germyl, boryl, alkenyl, cycloalkenyl, heteroalkenyl, aryl, heteroaryl, nitrile, isonitrile, sulfanyl, and combinations thereof.
In some instances, the More Preferred General Substituents are selected from the group consisting of deuterium, fluorine, alkyl, cycloalkyl, alkoxy, aryloxy, amino, silyl, germyl, boryl, aryl, heteroaryl, nitrile, sulfanyl, and combinations thereof.
In some instances, the Even More Preferred General Substituents are selected from the group consisting of deuterium, fluorine, alkyl, cycloalkyl, silyl, aryl, heteroaryl, nitrile, and combinations thereof.
In yet other instances, the Most Preferred General Substituents are selected from the group consisting of deuterium, alkyl, cycloalkyl, aryl, heteroaryl, and combinations thereof.
The terms “substituted” and “substitution” refer to a substituent other than H that is bonded to the relevant position, e.g., a carbon or nitrogen. For example, when R1 represents mono-substitution, then one R1 must be other than H (i.e., a substitution). Similarly, when R1 represents di-substitution, then two of R1 must be other than H. Similarly, when R1 represents zero or no substitution, R1, for example, can be a hydrogen for all available valencies of ring atoms, as in carbon atoms for benzene and the nitrogen atom in pyrrole, or simply represents nothing for ring atoms with fully filled valencies, e.g., the nitrogen atom in pyridine. The maximum number of substitutions possible in a ring structure will depend on the total number of available valencies in the ring atoms.
As used herein, “combinations thereof” indicates that one or more members of the applicable list are combined to form a known or chemically stable arrangement that one of ordinary skill in the art can envision from the applicable list. For example, an alkyl and deuterium can be combined to form a partial or fully deuterated alkyl group; a halogen and alkyl can be combined to form a halogenated alkyl substituent; and a halogen, alkyl, and aryl can be combined to form a halogenated arylalkyl. In one instance, the term substitution includes a combination of two to four of the listed groups. In another instance, the term substitution includes a combination of two to three groups. In yet another instance, the term substitution includes a combination of two groups. Preferred combinations of substituent groups are those that contain up to fifty atoms that are not hydrogen or deuterium, or those which include up to forty atoms that are not hydrogen or deuterium, or those that include up to thirty atoms that are not hydrogen or deuterium. In many instances, a preferred combination of substituent groups will include up to twenty atoms that are not hydrogen or deuterium.
The “aza” designation in the fragments described herein, i.e. aza-dibenzofuran, aza-dibenzothiophene, etc. means that one or more of the C—H groups in the respective aromatic ring can be replaced by a nitrogen atom, for example, and without any limitation, azatriphenylene encompasses both dibenzo[f,h]quinoxaline and dibenzo[f,h]quinoline. One of ordinary skill in the art can readily envision other nitrogen analogs of the aza-derivatives described above, and all such analogs are intended to be encompassed by the terms as set forth herein.
As used herein, “deuterium” refers to an isotope of hydrogen. Deuterated compounds can be readily prepared using methods known in the art. For example, U.S. Pat. No. 8,557,400, Patent Pub. No. WO 2006/095951, and U.S. Pat. Application Pub. No. US 2011/0037057, which are hereby incorporated by reference in their entireties, describe the making of deuterium-substituted organometallic complexes. Further reference is made to Ming Yan, et al., Tetrahedron 2015, 71, 1425-30 and Atzrodt et al., Angew. Chem. Int. Ed. (Reviews) 2007, 46, 7744-65, which are incorporated by reference in their entireties, describe the deuteration of the methylene hydrogens in benzyl amines and efficient pathways to replace aromatic ring hydrogens with deuterium, respectively.
As used herein, any specifically listed substituent, such as, without limitation, methyl, phenyl, pyridyl, etc. includes undeuterated, partially deuterated, and fully deuterated versions thereof. Similarly, classes of substituents such as, without limitation, alkyl, aryl, cycloalkyl, heteroaryl, etc. also include undeuterated, partially deuterated, and fully deuterated versions thereof. Unless otherwise specified, atoms in chemical structures without valences fully filled by H or D should be considered to include undeuterated, partially deuterated, and fully deuterated versions thereof. For example, the chemical structure of
implies to include C6H6, C6D6, C6H3D3, and any other partially deuterated variants thereof. Some common basic partially or fully deuterated groups include, without limitation, CD3, CD2C(CH3)3, C(CD3)3, and C6D5.
It is to be understood that when a molecular fragment is described as being a substituent or otherwise attached to another moiety, its name may be written as if it were a fragment (e.g. phenyl, phenylene, naphthyl, dibenzofuryl) or as if it were the whole molecule (e.g. benzene, naphthalene, dibenzofuran). As used herein, these different ways of designating a substituent or attached fragment are considered to be equivalent.
In some instances, a pair of substituents in the molecule can be joined or fused into a ring. The preferred ring is a five to nine-membered carbocyclic or heterocyclic ring, includes both instances where the portion of the ring formed by the pair of substituents is saturated and where the portion of the ring formed by the pair of substituents is unsaturated. In yet other instances, a pair of adjacent substituents can be joined or fused into a ring. As used herein, “adjacent” means that the two substituents involved can be on the same ring next to each other, or on two neighboring rings having the two closest available substitutable positions, such as 2, 2′ positions in a biphenyl, or 1, 8 position in a naphthalene.
Layers, materials, regions, and devices may be described herein in reference to the color of light they emit. In general, as used herein, an emissive region that is described as producing a specific color of light may include one or more emissive layers disposed over each other in a stack.
As used herein, a “NIR”, “red”, “green”, “blue”, “yellow” layer, material, region, or device refers to a layer, a material, a region, or a device that emits light in the wavelength range of about 700-1500 nm, 580-700 nm, 500-600 nm, 400-500 nm, 540-600 nm, respectively, or a layer, a material, a region, or a device that has a highest peak in its emission spectrum in the respective wavelength region. In some arrangements, separate regions, layers, materials, or devices may provide separate “deep blue” and “light blue” emissions. As used herein, the “deep blue” emission component refers to an emission having a peak emission wavelength that is at least about 4 nm less than the peak emission wavelength of the “light blue” emission component. Typically, a “light blue” emission component has a peak emission wavelength in the range of about 465-500 nm, and a “deep blue” emission component has a peak emission wavelength in the range of about 400-470 nm, though these ranges may vary for some configurations.
In some arrangements, a color altering layer that converts, modifies, or shifts the color of the light emitted by another layer to an emission having a different wavelength is provided. Such a color altering layer can be formulated to shift wavelength of the light emitted by the other layer by a defined amount, as measured by the difference in the wavelength of the emitted light and the wavelength of the resulting light. In general, there are two classes of color altering layers: color filters that modify a spectrum by removing light of unwanted wavelengths, and color changing layers that convert photons of higher energy to lower energy. For example, a “red” color filter can be present in order to filter an input light to remove light having a wavelength outside the range of about 580-700 nm. A component “of a color” refers to a component that, when activated or used, produces or otherwise emits light having a particular color as previously described. For example, a “first emissive region of a first color” and a “second emissive region of a second color different than the first color” describes two emissive regions that, when activated within a device, emit two different colors as previously described.
As used herein, emissive materials, layers, and regions may be distinguished from one another and from other structures based upon light initially generated by the material, layer or region, as opposed to light eventually emitted by the same or a different structure. The initial light generation typically is the result of an energy level change resulting in emission of a photon. For example, an organic emissive material may initially generate blue light, which may be converted by a color filter, quantum dot or other structure to red or green light, such that a complete emissive stack or sub-pixel emits the red or green light. In this case the initial emissive material or layer may be referred to as a “blue” component, even though the sub-pixel is a “red” or “green” component.
In some cases, it may be preferable to describe the color of a component such as an emissive region, sub-pixel, color altering layer, or the like, in terms of 1931 CIE coordinates. For example, a yellow emissive material may have multiple peak emission wavelengths, one in or near an edge of the “green” region, and one within or near an edge of the “red” region as previously described. Accordingly, as used herein, each color term also corresponds to a shape in the 1931 CIE coordinate color space. The shape in 1931 CIE color space is constructed by following the locus between two color points and any additional interior points. For example, interior shape parameters for red, green, blue, and yellow may be defined as shown below:
More details on OLEDs, and the definitions described above, can be found in U.S. Pat. No. 7,279,704, which is incorporated herein by reference in its entirety.
As disclosed herein, emissive layers or materials, such as emissive layer 135 and emissive layer 220 shown in
Unless otherwise specified, any of the layers of the various embodiments may be deposited by any suitable method. For the organic layers, preferred methods include thermal evaporation, ink-jet, such as described in U.S. Pat. Nos. 6,013,982 and 6,087,196, which are incorporated by reference in their entireties, organic vapor phase deposition (OVPD), such as described in U.S. Pat. No. 6,337,102 to Forrest et al., which is incorporated by reference in its entirety, and deposition by organic vapor jet printing (OVJP, also referred to as organic vapor jet deposition (OVJD)), such as described in U.S. Pat. No. 7,431,968, which is incorporated by reference in its entirety. Other suitable deposition methods include spin coating and other solution based processes. Solution based processes are preferably carried out in nitrogen or an inert atmosphere. For the other layers, preferred methods include thermal evaporation. Preferred patterning methods include deposition through a mask, cold welding such as described in U.S. Pat. Nos. 6,294,398 and 6,468,819, which are incorporated by reference in their entireties, and patterning associated with some of the deposition methods such as ink-jet and OVJD. Other methods may also be used. The materials to be deposited may be modified to make them compatible with a particular deposition method. For example, substituents such as alkyl and aryl groups, branched or unbranched, and preferably containing at least 3 carbons, may be used in small molecules to enhance their ability to undergo solution processing. Substituents having 20 carbons or more may be used, and 3-20 carbons is a preferred range. Materials with asymmetric structures may have better solution processibility than those having symmetric structures, because asymmetric materials may have a lower tendency to recrystallize. Dendrimer substituents may be used to enhance the ability of small molecules to undergo solution processing.
Devices fabricated in accordance with embodiments of the present disclosure may further optionally comprise a barrier layer. One purpose of the barrier layer is to protect the electrodes and organic layers from damaging exposure to harmful species in the environment including moisture, vapor and/or gases, etc. The barrier layer may be deposited over, under or next to a substrate, an electrode, or over any other parts of a device including an edge. The barrier layer may comprise a single layer, or multiple layers. The barrier layer may be formed by various known chemical vapor deposition techniques and may include compositions having a single phase as well as compositions having multiple phases. Any suitable material or combination of materials may be used for the barrier layer. The barrier layer may incorporate an inorganic or an organic compound or both. The preferred barrier layer comprises a plurality of alternative layers of polymeric material and non-polymeric material; organic material and inorganic material; or a mixture of a polymeric material and a non-polymeric material as one example described in U.S. Pat. No. 7,968,146, PCT Pat. Application Nos. PCT/US2007/023098 and PCT/US2009/042829, which are herein incorporated by reference in their entireties.
Devices fabricated in accordance with embodiments of the disclosure can be incorporated into a wide variety of electronic component modules (or units) that can be incorporated into a variety of electronic products or intermediate components. Examples of such electronic products or intermediate components include display screens, lighting devices such as discrete light source devices or lighting panels, etc. that can be utilized by the end-user product manufacturers. Such electronic component modules can optionally include the driving electronics and/or power source(s). Devices fabricated in accordance with embodiments of the disclosure can be incorporated into a wide variety of consumer products that have one or more of the electronic component modules (or units) incorporated therein. A consumer product comprising an OLED that includes the compound of the present disclosure in the organic layer in the OLED is disclosed. Such consumer products would include any kind of products that include one or more light source(s) and/or one or more of some type of visual displays. Some examples of such consumer products include a flat panel display, a curved display, a computer monitor, a medical monitor, a television, a billboard, a light for interior or exterior illumination and/or signaling, a heads-up display, a fully or partially transparent display, a flexible display, a rollable display, a foldable display, a stretchable display, a laser printer, a telephone, a cell phone, tablet, a phablet, a personal digital assistant (PDA), a wearable device, a laptop computer, a digital camera, a camcorder, a viewfinder, a micro-display that is less than 2 inches diagonal, a 3-D display, a virtual reality or augmented reality display, a vehicle, a video walls comprising multiple displays tiled together, a theater or stadium screen, and a sign. Various control mechanisms may be used to control devices fabricated in accordance with the present disclosure, including passive matrix and active matrix. Many of the devices are intended for use in a temperature range comfortable to humans, such as 18 C to 30 C, and more preferably at room temperature (20-25 C), but could be used outside this temperature range, for example, from −40 C to 80 C.
The materials and structures described herein may have applications in devices other than OLEDs. For example, other optoelectronic devices such as organic solar cells and organic photodetectors may employ the materials and structures. More generally, organic devices, such as organic transistors, may employ the materials and structures.
In general parlance in the art, a “sub-pixel” may refer to the emissive region, which may be a single-layer EML, a stacked device, or the like, in conjunction with any color altering layer that is used to modify the color emitted by the emissive region.
As used herein, the “emissive region” of a sub-pixel refers to any and all emissive layers, regions, and devices that are used initially to generate light for the sub-pixel. A sub-pixel also may include additional layers disposed in a stack with the emissive region that affect the color ultimately produced by the sub-pixel, such as color altering layers disclosed herein, though such color altering layers typically are not considered “emissive layers” as disclosed herein. An unfiltered sub-pixel is one that excludes a color modifying component such as a color altering layer, but may include one or more emissive regions, layers, or devices.
In some configurations, an “emissive region” may include emissive materials that emit light of multiple colors. For example, a yellow emissive region may include multiple materials that emit red and green light when each material is used in an OLED device alone. When used in a yellow device, the individual materials typically are not arranged such that they can be individually activated or addressed. That is, the “yellow” OLED stack containing the materials cannot be driven to produce red, green, or yellow light; rather, the stack can be driven as a whole to produce yellow light. Such an emissive region may be referred to as a yellow emissive region even though, at the level of individual emitters, the stack does not directly produce yellow light. As described in further detail below, the individual emissive materials used in an emissive region (if more than one), may be placed in the same emissive layer within the device, or in multiple emissive layers within an OLED device comprising an emissive region. As described in further detail below, embodiments disclosed herein may allow for OLED devices such as displays that include a limited number of colors of emissive regions, while including more colors of sub-pixels or other OLED devices than the number of colors of emissive regions. For example, a device as disclosed herein may include only blue and yellow emissive regions. Additional colors of sub-pixels may be achieved by the use of color altering layers, such as color altering layers disposed in a stack with yellow or blue emissive regions, or more generally through the use of color altering layers, electrodes or other structures that form a microcavity as disclosed herein, or any other suitable configuration. In some cases, the general color provided by a sub-pixel may be the same as the color provided by the emissive region in the stack that defines the sub-pixel, such as where a deep blue color altering layer is disposed in a stack with a light blue emissive region to produce a deep blue sub-pixel. Similarly, the color provided by a sub-pixel may be different than the color provided by an emissive region in the stack that defines the sub-pixel, such as where a green color altering layer is disposed in a stack with a yellow emissive region to product a green sub-pixel. In some other examples, a yellow sub-pixel may be composed of a red emissive region and a green emissive region. These regions may be separated by a CGL. A blue sub-pixel may be composed of several blue emissive regions and a green emissive region all in a stack.
In some configurations, emissive regions and/or emissive layers may span multiple sub-pixels, such as where additional layers and circuitry are fabricated to allow portions of an emissive region or layer to be separately addressable.
An emissive region as disclosed herein may be distinguished from an emissive “layer” as typically referred to in the art and as used herein. In some cases, a single emissive region may include multiple layers, such as where a yellow emissive region is fabricated by sequentially deposited red and green emissive layers to form the yellow emissive region. As previously described, when such layers occur in an emissive region as disclosed herein, the layers are not individually addressable within a single emissive stack; rather, the layers are activated or driven concurrently to produce the desired color of light for the emissive region. In other configurations, an emissive region may include a single emissive layer of a single color, or multiple emissive layers of the same color, in which case the color of such an emissive layer will be the same as, or in the same region of the spectrum as, the color of the emissive region in which the emissive layer is disposed.
In one aspect, the present disclosure provides a pixel arrangement of a device comprising at least one pixel, wherein the at least one pixel comprises:
In some embodiments, at least one of the following conditions is true:
In some embodiments, the compound A1 is a blue emitter, and the compound A2 is a green emitter.
In some embodiments, each of compounds A1 and A2 is independently a blue emitter. In some embodiments, the compounds A1 and A2 can be the same. In some embodiments, the compounds A1 and A2 can be different. In some embodiments, one can be deep blue, the other one can be light blue.
In some embodiments, the compound A1 is a blue emitter, the compound A2 is a yellow emitter.
In some embodiments, the first subpixel is configured to emit blue light.
In some embodiments, the second subpixel is configured to emit green light.
In some embodiments, the first OLED (1) further comprises an emissive region ER12, wherein ER12 can be same or different from ER11. In some embodiments, ER12 is the same as ER11. In some embodiments, ER12 is different from ER11. In some embodiments, ER12 does not comprise a sensitizing device. In some embodiments, ER12 is a sensitizing device, but with at least one sensitizer or acceptor being different from that in ER11. In some embodiments, ER11 and ER12 are configured to emit the same color. In some embodiments, the first OLED (1) comprises a CGL between the ER11 and ER12. In some such embodiments, OLED (1) may be configurated to be an OLED (5). In such embodiments, all the OLED (5) related embodiments can be equally applied herein.
In some embodiments, the second OLED (2) further comprises an emissive region ER22, wherein ER22 can be same or different from ER21. In some embodiments, ER22 is the same as ER21. In some embodiments, ER22 is different from ER21. In some embodiments, ER22 does not comprise a sensitizing system. In some embodiments, ER22 is a sensitizing device, but with at least one sensitizer or acceptor being different from that in ER21. In some embodiments, ER21 and ER22 are configured to emit the same color. In some embodiments, the second OLED (2) comprises a CGL between the ER21 and ER22. In some such embodiments, OLED (1) may be configurated to be an OLED (5). In such embodiments, all the OLED (5) related embodiments can be equally applied herein.
In some embodiments, each of the first, and second OLEDs independently comprises N1 number of the emissive regions, wherein N1 is an integer from 1 to 10. In some embodiments, each of the first, and second OLEDs independently comprises N1 number of the emissive regions, wherein N1 is an integer from 1 to 5. In some embodiments, each of the first and second OLEDs comprise the same number of the emissive regions.
In some embodiments, each of the first and second OLEDs independently comprises a plurality of the emissive regions wherein each of the plurality of the emissive regions has identical or same components and arrangements. Put it another way, each of the plurality of the emissive regions is the same as the other.
In some embodiments, the compound S1 is the same as the compound S2. In some embodiments, the compound A1 is the same as the compound A2. In some embodiments, the compound S1 is the same as the compound S2, and the compound A1 is the same as the compound A2. In some such embodiments, the first subpixel may be configured to generate a different color than the second subpixel. This may be achieved by use of color filters.
In some embodiments, the at least one pixel further comprises a third subpixel comprising a third OLED (3) comprising an emissive region ER31. In some embodiments, the third subpixel doesn't comprise any sensitizing system.
In some of the above embodiments, the ER31 comprises:
In some of the above embodiments, at least one of the following conditions is true:
In some of the above embodiments, the compound A1 is a blue emitter, the compound A2 is a green emitter; and the compound A3 is a red emitter.
In some of the above embodiments, each of the compounds A1, A2, and A3 is independently a blue emitter. In some of these embodiments, the compounds A1, A2, and A3 can be the same. In some of these embodiments, the compounds A1, A2, and A3 can be different.
In some of the above embodiments, the first subpixel is configured to emit blue light, the second subpixel is configured to emit green light, and the third subpixel is configured to emit red light.
In some of the above embodiments, the third OLED (3) further comprises an emissive region ER32; wherein ER32 can be same or different from ER31. In some embodiments, ER32 is the same as ER31. In some embodiments, ER32 is different from ER31. In some embodiments, ER32 does not comprise a sensitizing device. In some embodiments, ER32 is a sensitizing device, but with at least one sensitizer or acceptor being different from that in ER31. In some embodiments, ER31 and ER32 are configured to emit the same color. In some embodiments, the third OLED (3) comprises a CGL between the ER31 and ER32. In some such embodiments, OLED (1) may be configurated to be an OLED (5). In such embodiments, all the OLED (5) related embodiments can be equally applied herein.
In some of the above embodiments, each of OLED (1), OLED (2) and OLED (3) independently comprises N1 number of the emissive region, wherein N1 is an integer from 1 to 10. In some of the above embodiments, each of OLED (1), OLED (2) and OLED (3) independently comprises N1 number of the emissive region, wherein N1 is an integer from 1 to 5.
In some of the above embodiments, each of OLED (1), OLED (2) and OLED (3) comprises the same number of the emissive regions.
In some of the above embodiments, each of OLED (1), OLED (2) and OLED (3) independently comprises a plurality of the emissive regions while each of the plurality of the emissive regions has identical or same components and arrangements. Put it another way, in some embodiments, each of the plurality of the emissive regions is the same as the other. In some embodiments, each of the plurality of the emissive regions in a given OLED (e.g., OLED (1), OLED (2), or OLED (3)) is the same as the others.
In some embodiments, the at least one pixel further comprises a fourth subpixel comprising a fourth OLED (4) comprising an emissive region ER41.
In some embodiments, the at least one pixel comprises a plurality of subpixels; and each of the plurality of subpixels comprises a sensitizer and an acceptor to form a sensitizing system.
In some embodiments, the pixel arrangement further comprises quantum dots. In some embodiments, the pixel arrangement further comprises a color filter or a color altering layer. In some embodiments, the pixel arrangement provides a Rec2020 color gamut. In some embodiments, the pixel arrangement further comprises a subpixel comprising an emissive region being configured to emit a NIR color. This subpixel can be under the at least one pixel or another independent pixel solely designated/designed for NIR. In some embodiments, the pixel arrangement further comprises a color altering layer. It should be understood that the color altering layer can be a color conversion layer, a color filter, a downconversion filter, a band-pass filter, or a cut-off filter. In some embodiments, the pixel arrangement comprises a first subpixel and a second subpixel, the first subpixel has a first optical path length, the second subpixel has a second optical path length different than the first optical path length. The optical path length is modified by one of the following: patterning of an electrode thickness, addition of an optical metamaterial, or modification of composition or thickness for layers that are not in the emissive region. In some embodiments, the at least one pixel comprises a plurality of subpixels; wherein only one of the plurality of subpixels has a color altering layer.
In another aspect, the present disclosure also provides an organic light emitting device (OLED (5)) comprising:
In some embodiments, at least one of the following conditions is true:
In some embodiments, each of the compounds A1′ and A2′ is independently an emitter with an emitting color of blue, green, yellow, red, or NIR. In some embodiments, the compounds A1′ and A2′ are the same. In some embodiments, the compounds A1′ and A2′ are different but with the same emitting color with the difference of their λmax being less than 20, 15, 10, 8, 6, or 4 nm. In some embodiments, the compounds A1′ and A2′ are different with different emitting colors.
In some embodiments, the OLED (5) further comprises:
In some of the above embodiments, the ER31′ does not comprise a sensitizer.
In some of the above embodiments, the ER31′ comprises:
In some of the above embodiments, at least one of the following conditions is true:
In some of the above embodiments, the compound A3′ is an emitter with an emitting color of blue, green, yellow, red, or NIR. In some embodiments, the compounds A1′, A2′ and A3′ are the same. In some embodiments, the compounds A1′, A2′ and A3′ are different from each other but with the same emitting color with the difference of their λmax being less than 20, 15, 10, 8, 6, or 4 nm. In some embodiments, the compounds A1′, A2′ and A3′ are different from each other with different emitting colors. In some embodiments, two of the compounds A1′, A2′ and A3′ have the same emitting colors but different from the remaining one.
In some embodiments, the OLED (5) further comprises:
In some embodiments, the ER41′ does not comprise a sensitizer.
In some embodiments, the ER41′ comprises:
In some embodiments, at least one of the following conditions is true:
In some embodiments, the compound A4′ is an emitter with an emitting color of blue, green, yellow, red, or NIR. In some embodiments, the compounds A1′, A2′, A3′, and A4′ are the same. In some embodiments, the compounds A1′, A2′, A3′, and A4′ are different from each other but with the same emitting color with the difference of their λmax being less than 20, 15, 10, 8, 6, or 4 nm. In some embodiments, the compounds A1′, A2′, A3′, and A4′ are different from each other with different emitting colors. In some embodiments, two of the compounds A1′, A2′, A3′, and A4′ have the same emitting colors but different from the remaining two compounds. In some embodiments, three of the compounds A1′, A2′, A3′, and A4′ have the same emitting colors but different from the remaining one compound.
In some embodiments, the OLED (5) as described above comprises a plurality of emissive regions, wherein at least one of the plurality of emissive regions comprises two or more emissive layers, and each of the two or more emissive layers independently comprises an emitter with an emitting color of blue, green, yellow, red, or NIR. In some embodiments, at least one of the plurality of emissive regions comprises exactly two emissive layers. In some such embodiments, each of the two emissive layers comprises an emitter with each emitting a different color selected from any combination of the colors mentioned above, including NIR, red, green, blue, and yellow. In some embodiments, at least one of the emissive regions comprises exactly three emissive layers. In some such embodiments, each of the three emissive layers comprises an emitter with each emitting a different color (three different colors), where each of the colors is selected from any of the colors mentioned above, including NIR, red, green, blue, and yellow. For example, the first one comprises an emitter which emits red (red emitter), the second one comprises an emitter which emits yellow (yellow emitter), and the third one comprises an emitter which emits green (green emitter). In some embodiments, each emissive layer mentioned here can be a sensitizing system, or a non-sensitizing system.
In some embodiments, the OLED (5) comprises a plurality of emissive regions, wherein each of the emissive regions comprises a sensitizer and an acceptor to form a sensitizing system.
In some embodiments, the OLED (5) is configurated to emit white color.
In some embodiments, the OLED (5) comprises exactly two emissive regions, ER11′ and ER21′ only. In some embodiments, the OLED (5) comprises exactly three emissive regions, ER11′, ER21′, and ER31′ only. In some embodiments, the OLED (5) comprises exactly four emissive regions, ER11′, ER21′, ER31′, and ER41′ only.
In some embodiments, the OLED (5) further comprises a color conversion layer or a color filter.
In yet another aspect, the present disclosure further provides a consumer product comprising a pixel arrangement as described herein. In yet another aspect, the present disclosure further provides a consumer product comprising an OLED (5) as described herein.
In some embodiments, the consumer product is selected from the group consisting of a flat panel display, a computer monitor, a medical monitor, a television, a billboard, a light for interior or exterior illumination and/or signaling, a heads-up display, a fully or partially transparent display, a flexible display, a laser printer, a telephone, a cell phone, tablet, a phablet, a personal digital assistant (PDA), a wearable device, a laptop computer, a digital camera, a camcorder, a viewfinder, a micro-display that is less than 2 inches diagonal, a 3-D display, a virtual reality or augmented reality display, a vehicle, a video wall comprising multiple displays tiled together, a theater or stadium screen, a light therapy device, and a sign.
It should be understood that the basic characteristics and/or features of a sensitizer described herein can be equally applied to all the sensitizers such as S1 to S3, and S1′ to S4′ as described throughout the present disclosure. Likewise, the basic characteristics and/or features of an acceptor described herein can be equally applied to all the sensitizers such as A1 to A3, and A1′ to A4′ as described throughout the present disclosure.
It should also be understood that when it comes to the relationships such as, but not limited to, energy level, energy difference, spectral overlap, and VDR combinations between an acceptor and a sensitizer, it refers to a specific pair in the disclosure unless specified otherwise. For example, the sensitizer S1 is paired with the acceptor A1. Likewise, the sensitizer S2 is paired with the acceptor A2; the sensitizer S3 is paired with the acceptor A3; the sensitizer S1′ is paired with the acceptor A1′; the sensitizer S2′ is paired with the acceptor 2′; the sensitizer S3′ is paired with the acceptor A3′; and the sensitizer S4′ is paired with the acceptor A4′.
In some embodiments, an OLED of the present disclosure comprises an emissive region disposed between the anode and the cathode; wherein the emissive region comprises a sensitizer compound and an acceptor compound; wherein the sensitizer transfers energy to the acceptor compound that is an emitter. In some embodiments, the sensitizer compound is capable of emitting light from a triplet excited state to a ground singlet state in an OLED at room temperature. In some embodiments, the sensitizer compound is capable of functioning as a phosphorescent emitter, a TADF emitter, or a doublet emitter in an OLED at room temperature, they are also referred as a phosphorescent material, a TADF material, or a doublet material. In some embodiments, the acceptor compound is selected from the group consisting of: a delayed-fluorescent material functioning as a TADF emitter in the OLED at room temperature, a delayed-fluorescent material functioning as a non-delayed fluorescent emitter in the OLED at room temperature a non-delayed fluorescent material functioning as a non-delayed fluorescent emitter in the OLED at room temperature, and a non-delayed fluorescent material functioning as a delayed fluorescent emitter in the OLED at room temperature. In some embodiments, the fluorescent emitter can be a singlet or doublet emitters. In some of such embodiments, the singlet emitter can also include a TADF emitter, furthermore, a multi-resonant MR-TADF emitter. Description of the delayed fluorescence as used herein can be found in U.S. application publication US20200373510A1, at paragraphs 0083-0084, the entire contents of which are incorporated herein by reference.
In some embodiments, each of the compounds S1, S2, and S3 is a phosphorescent material at room temperature. In some embodiments, at least one of the compound S1, S2, or S3 is a phosphorescent material at room temperature, and at least one of the compound S1, S2, or S3 is a delayed fluorescent material at room temperature. In some embodiments, each of the compounds S1, S2, and S3 is a delayed fluorescent material at room temperature. In some embodiments, each of the compounds A1, A2, and A3 is a delayed fluorescent material at room temperature. In some embodiments, at least one of the compound A1, A2, or A3 is a delayed fluorescent material at room temperature and at least one of the compound A1, A2, or A3 is a non-delayed fluorescent material at room temperature. In some embodiments, each of the compounds A1, A2, and A3 is a non-delayed fluorescent material at room temperature. In some embodiments, the delayed fluorescent material is a TADF material at room temperature.
In some embodiments, each of the compounds S1′, S2′, S3′, and S4′ is a phosphorescent material at room temperature. In some embodiments, at least one of the compound S1′, S2′, S3′, or S4′ is a phosphorescent material at room temperature, and at least one of the compound S1′, S2′, S3′, or S4′ is a delayed fluorescent material at room temperature. In some embodiments, each of the compounds S1′, S2′, S3′, and S4′ is a delayed fluorescent material at room temperature. In some embodiments, each of the compounds A1′, A2′, A3′, and A4′ is a delayed fluorescent material at room temperature. In some embodiments, at least one of the compound A1′, A2′, A3′, or A4′ is a delayed fluorescent material at room temperature and at least one of the compound A1′, A2′, A3′, or A4′ is a non-delayed fluorescent material at room temperature. In some embodiments, each of the compounds A1′, A′2, A3′, and A4′ is a non-delayed fluorescent material at room temperature. In some embodiments, the delayed fluorescent material is a TADF material at room temperature.
In some embodiments of an OLED such as OLED (1), OLED (2), OLED (3), OLED (4), or OLED (5) as described herein, the sensitizer and acceptor compounds are in separate layers within the emissive region. In some embodiments, each emissive region is defined by one or more emissive layers between two CGL or one or more emissive layers between an electrode and a charge generation layer.
In some embodiments, the sensitizer and the acceptor compounds are present as a mixture in one or more layers in the emissive region. It should be understood that the mixture in a given layer can be a homogeneous mixture or the compounds in the mixture can be in varied concentrations through the thickness of the given layer. The concentration variance can be linear, non-linear, graded, sinusoidal, etc. When there is more than one layer in the emissive region having a mixture of the sensitizer and the acceptor compounds, the type of mixture (i.e., homogeneous or varied concentration) and the concentration levels of the compounds in the mixture in each of the more than one layer can be the same or different. In addition to the sensitizer and the acceptor compounds, there can be one or more other functional compounds such as, but not limit to, hosts also mixed into the mixture.
In some embodiments, the acceptor compound can be in two or more layers with the same or different concentration. In some embodiments, when two or more layers contain the acceptor compound, the concentrations of the acceptor compound in at least two of the two or more layers are different. In some embodiments, the concentration of sensitizer compound in the layer containing the sensitizer compound is in the range of 1 to 50%, 10 to 20%, or 12-15% by weight. In some embodiments, the concentration of the acceptor compound in the layer containing the acceptor compound is in the range of 0.1 to 10%, 0.5 to 5%, or 1 to 3% by weight.
In some embodiments, the emissive region contains N layers where N>2. In some embodiments, the sensitizer compound is present in each of the N layers, and the acceptor compound is contained in fewer than or equal to N−1 layers. In some embodiments, the sensitizer compound is present in each of the N layers, and the acceptor compound is contained in fewer than or equal to N/2 layers. In some embodiments, the acceptor compound is present in each of the N layers, and the sensitizer compound is contained in fewer than or equal to N−1 layers. In some embodiments, the acceptor compound is present in each of the N layers, and the sensitizer compound is contained in fewer than or equal to N/2 layers.
In some embodiments, an OLED such as OLED (1), OLED (2), OLED (3), OLED (4), or OLED (5) as described herein emits a luminescent emission comprising an emission component from the S1 energy (the first singlet energy) of the acceptor compound when a voltage is applied across the OLED. In some embodiments, at least 65%, 75%, 85%, or 95% of the emission from the OLED is produced from the acceptor compound with a luminance of at least 10 cd/m2. In some embodiments, S1 energy of the acceptor compound is lower than that of the sensitizer compound.
In some embodiments, a T1 energy (the first triplet energy) of the host compound is greater than or equal to the T1 energies of the sensitizer compound and the acceptor compound, and the T1 energy of the sensitizer compound is greater than or equal to the Si energy (the first singlet energy) of the acceptor compound. In some embodiments, S1-T1 energy gap of the sensitizer compound, and/or acceptor compound, and/or first host compound, and/or second host compound is less than 400, 300, 250, 200, 150, 100, or 50 meV. In some embodiments, the absolute energy difference between the HOMO of the sensitizer compound and the HOMO of the acceptor compound is less than 0.6, 0.5, 0.4, 0.3, or 0.2 eV. In some embodiments, the absolute energy difference between the LUMO of the sensitizer compound and the LUMO of the acceptor compound is less than 0.6, 0.5, 0.4, 0.3, or 0.2 eV. It should also be understood that the host compound referred to should be mixed with the corresponding sensitizer compound and/or the acceptor compound.
In some embodiments where the sensitizer compound provides unicolored sensitization (i.e., minimal loss in energy upon energy transfer to the acceptor compound), the acceptor compound has a Stokes shift of 30, 25, 20, 15, or 10 nm or less. An example would be a broad blue phosphor sensitizing a narrow blue emitting acceptor.
In some embodiments where the sensitizer compound provides a down conversion process (e.g., a blue emitter being used to sensitize a green emitter, or a green emitter being used to sensitize a red emitter), the acceptor compound has a Stokes shift of 30, 40, 60, 80, or 100 nm or more. In some embodiments, even though the acceptor is providing a down conversion process, the acceptor compound has a Stokes shift of 30, 25, 20, 15, or 10 nm or less.
In some embodiments, the difference between λmax of the emission spectrum of the sensitizer and λmax of the absorption spectrum of the acceptor is 50, 40, 30, or 20 nm or less. In some embodiments, the difference between λmax of the emission spectrum of the sensitizer and λmax of the absorption spectrum of the acceptor is negative, for example, −5 nm. This may occur with a broad spectrum sensitizer and a narrow spectrum acceptor. In some embodiments, the spectral overlap of the light absorbing area of the acceptor and the light emitting area of the sensitizer, relative to the light emitting area of the sensitizer, is greater than 5%, 10%, 15%, 20%, 30%, 40%, 50%, or more. As examples and/or more particularly, the difference between λmax as defined above should be between the sensitizer S1 and the acceptor A1, between the sensitizer S2 and the acceptor A2, between the sensitizer S3 and the acceptor A3, between the sensitizer S1′ and the acceptor A1′, between the sensitizer S2′ and the acceptor 2′, between the sensitizer S3′ and the acceptor A3′, or between the sensitizer S4′ and the acceptor A4′.
One way to quantify the qualitative relationship between a sensitizer compound (a compound to be used as the sensitizer in the emissive region of the OLED of the present disclosure) and an acceptor compound (a compound to be used as the acceptor in the emissive region of an OLED of the present disclosure) is by determining a value Δλ=λmax1−λmax2, where λmax1 and λmax2 are defined as follows. λmax1 is the emission maximum of the sensitizer compound at room temperature when the sensitizer compound is used as the sole emitter in a first monochromic OLED (an OLED that emits only one color) that has a first host. λmax2 is the emission maximum of the acceptor compound at room temperature when the acceptor compound is used as the sole emitter in a second monochromic OLED that has the same first host. As examples and/or more particularly, Δλ as defined above should be between the sensitizer S1 and the acceptor A1, between the sensitizer S2 and the acceptor A2, between the sensitizer S3 and the acceptor A3, between the sensitizer S1′ and the acceptor A1′, between the sensitizer S2′ and the acceptor 2′, between the sensitizer S3′ and the acceptor A3′, or between the sensitizer S4′ and the acceptor A4′.
In some embodiments of an OLED of the present disclosure where the sensitizer compound provides unicolored sensitization (i.e., minimal loss in energy upon energy transfer to the acceptor compound), Δλ (determined as described above) is equal to or less than the number selected from the group consisting of 15, 12, 10, 8, 6, 4, 2, 0, −2, −4, −6, −8, and −10 nm. As examples and/or more particularly, Δλ as defined above should be between the sensitizer S1 and the acceptor A1, between the sensitizer S2 and the acceptor A2, between the sensitizer S3 and the acceptor A3, between the sensitizer S1′ and the acceptor A1′, between the sensitizer S2′ and the acceptor 2′, between the sensitizer S3′ and the acceptor A3′, and between the sensitizer S4′ and the acceptor A4′.
In some embodiments, a spectral overlap integral of the acceptor compound and the sensitizer compound is at least 1014 nm4*L/cm*mol. In some embodiments, a spectral overlap integral of the acceptor compound and the sensitizer compound is at least 5×1014 nm4*L/cm*mol. In some embodiments, a spectral overlap integral of the acceptor compound and the sensitizer compound is at least 1015 nm4*L/cm*mol. As examples and/or more particularly, the spectral overlap integral as defined above should be between the sensitizer S1 and the acceptor A1, between the sensitizer S2 and the acceptor A2, between the sensitizer S3 and the acceptor A3, between the sensitizer S1′ and the acceptor A1′, between the sensitizer S2′ and the acceptor 2′, between the sensitizer S3′ and the acceptor A3′, or between the sensitizer S4′ and the acceptor A4′.
As used herein, “spectral overlap integral” is determined by multiplying the acceptor compound extinction spectrum by the sensitizer compound emission spectrum normalized with respect to the area under the curve. The higher the spectral overlap, the better the Förster Resonance Energy Transfer (FRET) efficiency. The rate of FRET is proportional to the spectral overlap integral. Therefore, a high spectral overlap can help improve the FRET efficiency and reduce the exciton lifetime in an OLED.
In some embodiments, the acceptor compound and the sensitizer compound are selected in order to increase the spectral overlap. Increasing the spectral overlap can be achieved in several ways, for example, increasing the oscillator strength of the acceptor compound, minimizing the distance between the sensitizer compound peak emission intensity and the acceptor compound absorption peak, and narrowing the line shape of the sensitizer compound emission or the acceptor compound absorption. In some embodiments, the oscillator strength of the acceptor compound is greater than or equal to 0.1.
In some embodiments where the emission of the acceptor is redshifted by the sensitization, the absolute value of Δλ is equal to or greater than the number selected from the group consisting of 20, 30, 40, 60, 80, 100 nm.
In the embodiments, the sensitizer compound is a phosphorescent material, and the sensitizer compound can be a metal coordination complex having a metal-carbon bond, a metal-nitrogen bond, or a metal-oxygen bond. In some embodiments, the metal is selected from the group consisting of Ir, Rh, Re, Ru, Os, Pt, Pd, Zn, Zr, Au, Ag, and Cu. In some embodiments, the metal is Ir. In some embodiments, the metal is Pt. In some embodiments, the sensitizer compound has the formula of M(L′)x(L2)y(L3)z;
wherein L2 and L3 are independently selected from the group consisting of
and the structures of LIGAND LIST; wherein:
In some embodiments, the metal in formula M(L′)x(L2)y(L3)z is selected from the group consisting of Cu, Ag, or Au.
In some embodiments of an OLED such as OLED (1), OLED (2), OLED (3), OLED (4), or OLED (5) as described herein, the sensitizer compound has a formula selected from the group consisting of Ir(LA)3, Ir(LA)(LB)2, Ir(LA)2(LB), Ir(LA)2(LC), Ir(LA)(LB)(LC), and Pt(LA)(LB);
In some embodiments of an OLED such as OLED (1), OLED (2), OLED (3), OLED (4), or OLED (5) as described herein, the sensitizer compound is selected from the group consisting of the compounds in the following SENSITIZER LIST:
In some embodiments of an OLED such as OLED (1), OLED (2), OLED (3), OLED (4), or OLED (5) as described herein where the sensitizer is selected from the group consisting of the structures in the SENSITIZER LIST, one or more of R, R′, R″, R′″, R10a, R11a, R12a, R13a, R20a, R30a, R40a, R50a, R60, R70, R97, R98, R99, RA1′, RA2′, RA″, RB″, RC″, RD′, RE″, RF″, RG″, RH″, RI″, RJ″, RK″, RL″, RM″, and RN″ comprises a moiety selected from the group consisting of fully or partially deuterated aryl, fully or partially deuterated alkyl, boryl, silyl, germyl, 2,6-terphenyl, 2-biphenyl, 2-(tert-butyl)phenyl, tetraphenylene, tetrahydronaphthalene, and combinations thereof.
In some embodiments, the sensitizer and/or the acceptor can be a phosphorescent or fluorescent material/emitter. Phosphorescence generally refers to emission of a photon with a change in electron spin quantum number, i.e., the initial and final states of the emission have different electron spin quantum numbers, such as from T1 to S0 state. Most of the Ir and Pt complexes currently used in OLEDs are phosphorescent emitters. In some embodiments, if an exciplex formation involves a triplet emitter, such exciplex can also emit phosphorescent light. On the other hand, fluorescent emitters generally refer to emission of a photon without a change in electron spin quantum number, such as from S1 to S0 state, or from D1 to D0 state. Fluorescent emitters can be delayed fluorescent or non-delayed fluorescent emitters. Depending on the spin state, fluorescent emitter can be a singlet emitter or a doublet emitter, or other multiplet emitter. It is believed that the internal quantum efficiency (IQE) of fluorescent OLEDs can exceed the 25% spin statistics limit through delayed fluorescence. There are two types of delayed fluorescence, i.e. P-type and E-type delayed fluorescence. P-type delayed fluorescence is generated from triplet-triplet annihilation (TTA). On the other hand, E-type delayed fluorescence does not rely on the collision of two triplets, but rather on the thermal population between the triplet states and the singlet excited states. Thermal energy can activate the transition from the triplet state back to the singlet state. This type of delayed fluorescence is also known as thermally activated delayed fluorescence (TADF). E-type delayed fluorescence characteristics can be found in an exciplex system or in a single compound. Without being bound by theory, it is believed that TADF requires a compound or an exciplex having a small singlet-triplet energy gap (ΔES-T) less than or equal to 400, 350, 300, 250, 200, 150, 100, or 50 meV. There are two major types of TADF emitters, one is called donor-acceptor type TADF, the other one is called multiple resonance (MR) TADF. Often, donor-acceptor single compounds are constructed by connecting an electron donor moiety such as amino- or carbazole-derivatives and an electron acceptor moiety such as N-containing six-membered aromatic rings or cyano-substituted aromatic rings. Donor-acceptor exciplex can be formed between a hole transporting compound and an electron transporting compound. The examples for MR-TADF include highly conjugated fused ring systems. In some embodiments, MR-TADF materials comprise boron, carbon, and nitrogen atoms. They may comprise other atoms as well, for example oxygen. In some embodiments, the reverse intersystem crossing time from T1 to S1 of the delayed fluorescent emission at 293K is less than or equal to 10 microseconds. In some embodiments, such time can be greater than 10 microseconds and less than 100 microseconds.
In some embodiments of an OLED such as OLED (1), OLED (2), OLED (3), OLED (4), or OLED (5) as described herein, at least one of the following conditions is true:
In some embodiments of an OLED such as OLED (1), OLED (2), OLED (3), OLED (4), or OLED (5) as described herein, the delayed fluorescence material comprises at least one donor group and at least one acceptor group. In some embodiments, the delayed fluorescence material is a metal complex. In some embodiments, the delayed fluorescence material is a non-metal complex. In some embodiments, the delayed fluorescence material is a Pt, Pd, Zn, Cu, Ag, or Au complex (some of them are also called metal-assisted (MA) TADF). In some embodiments, the metal-assisted delayed fluorescence material comprises a metal-carbene bond. In some embodiments, the non-delayed fluorescence material or delayed fluorescence material comprises at least one chemical group selected from the group consisting of aryl-amine, aryloxy, arylthio, triphenylene, carbazole, indolocarbazole, dibenzothiophene, dibenzofuran, dibenzoselenophene, 5λ2-benzo[d]benzo[4,5]imidazo[3,2-a]imidazole, 5,9-dioxa-13b-boranaphtho[3,2,1-de]anthracene, 5λ2,9λ2-diaza-13b-boranaphtho[2,3,4-de]anthracene, 5-oxa-9λ2-aza-13b-boranaphtho[3,2,1-de]anthracene, azaborinine, oxaborinine, dihydroacridine, xanthene, dihydrobenzoazasiline, dibenzooxasiline, phenoxazine, phenoxathiine, phenothiazine, dihydrophenazine, fluorene, naphthalene, anthracene, phenanthrene, phenanthroline, benzoquinoline, quinoline, isoquinoline, quinazoline, pyrimidine, pyrazine, pyridine, triazine, boryl, amino, silyl, aza-variants thereof, and combinations thereof. In some embodiments, non-delayed the fluorescence material or delayed fluorescence material comprises a tri(aryl/heteroaryl)borane with one or more pairs of the substituents from the aryl/heteroaryl being joined to form a ring. In some embodiments, the fluorescence material comprises at least one chemical group selected from the group consisting of naphthalene, anthracene, phenalene, phenanthrene, fluorene, pyrene, chrysene, perylene, and azulene.
In some embodiments of an OLED such as OLED (1), OLED (2), OLED (3), OLED (4), or OLED (5) as described herein, the TADF material has the formula of M(L5)(L6), wherein M is Cu, Ag, or Au, L5 and L6 are different, and L5 and L6 are independently selected from the group consisting of:
In some embodiments of an OLED such as OLED (1), OLED (2), OLED (3), OLED (4), or OLED (5) as described herein, the TADF material is selected from the group consisting of:
In some embodiments of an OLED such as OLED (1), OLED (2), OLED (3), OLED (4), or OLED (5) as described herein, the TADF material is selected from the group consisting of:
In some embodiments of an OLED such as OLED (1), OLED (2), OLED (3), OLED (4), or OLED (5) as described herein, the TADF material comprises a boron atom. In some embodiments of an OLED such as OLED (1), OLED (2), OLED (3), OLED (4), or OLED (5) as described herein, the TADF material comprises at least one of the donor moieties selected from the group consisting of:
In some of the above embodiments, any carbon ring atoms up to maximum of a total number of three, together with their substituents, in each phenyl ring of any of above structures can be replaced with N.
In some embodiments, the TADF material comprises at least one of the acceptor moieties selected from the group consisting of nitrile, isonitrile, borane, fluoride, pyridine, pyrimidine, pyrazine, triazine, aza-carbazole, aza-dibenzothiophene, aza-dibenzofuran, aza-dibenzoselenophene, aza-triphenylene, imidazole, pyrazole, oxazole, thiazole, isoxazole, isothiazole, triazole, thiadiazole, and oxadiazole. In some embodiments, the acceptor moieties and the donor moieties as described herein can be connected directly, through a conjugated linker, or a non-conjugated linker, such as a sp3 carbon or silicon atom.
In some embodiments, the acceptor is a fluorescent material. In some embodiments, the fluorescent compound comprises at least one of the chemical moieties selected from the group consisting of:
In some of the above embodiments, any carbon ring atoms up to maximum of a total number of three, together with their substituents, in each phenyl ring of any of above structures can be replaced with N.
In some embodiments of an OLED such as OLED (1), OLED (2), OLED (3), OLED (4), or OLED (5) as described herein, the fluorescent compound is selected from the group consisting of:
In some embodiments, the acceptor compound is selected from the group consisting of the structures of the following ACCEPTOR LIST:
aza-substituted variants thereof, fully or partially deuterated variants thereof, and combinations thereof.
In some of the above embodiments, any carbon ring atoms up to maximum of a total number of three, together with their substituents, in each phenyl ring of any of above structures can be replaced with N.
In some embodiments, the acceptor compound comprises a fused ring system having at least five to fifteen 5-membered and/or 6-membered aromatic rings. In some embodiments, the acceptor compound has a first group and a second group with the first group not overlapping with the second group; wherein at least 80% of the singlet excited state population of the lowest singlet excitation state are localized in the first group; and wherein at least 80%, 85%, 90%, or 95% of the triplet excited state population of the lowest triplet excitation state are localized in the second group.
In some embodiments, the emissive region further comprises a first host. In some embodiments, the sensitizer compound forms an exciplex with the first host in the emissive region in an OLED such as OLED (1), OLED (2), OLED (3), OLED (4), or OLED (5) as described herein at room temperature. In some embodiments, the first host has a LUMO energy that is lower than the LUMO energies of the sensitizer compound and the acceptor compound in the emissive region. In some embodiments, the first host has a HOMO energy that is lower than the HOMO energies of the sensitizer compound and the acceptor compound in the emissive region. In some embodiments, the first host has a HOMO energy that is higher than the HOMO energies of the sensitizer compound and the acceptor compound in the emissive region. In some embodiments, the first host has a HOMO energy that is higher than the HOMO energy of at least one of the sensitizer compound and the acceptor compound in the emissive region.
In some embodiments, the emissive region further comprises a second host. In some embodiments, the first host forms an exciplex with the second host in the emissive region in an OLED such as OLED (1), OLED (2), OLED (3), OLED (4), or OLED (5) as described herein at room temperature. In some embodiments, the S1-T1 energy gap in the exciplex formed by the first host and the second host is less than 0.4, 0.3, 0.2, or 0.1 eV. In some embodiments, the T1 energy of exciplex is greater than 2.5, 2.6, 2.7, or 2.8 eV. In some embodiments, the concentrations of the first and second hosts in the layer or layers containing the first and second host are greater than the concentrations of the sensitizer compound and the acceptor compound in the layer or layers containing the sensitizer compound and the acceptor compound. In some embodiments, the concentrations of the first and second hosts in the layer or layers containing the first and second host are greater than the concentrations of the acceptor compound in the layer or layers containing the sensitizer compound and the acceptor compound.
In some embodiments, the Si energy of the first host is greater than that of the acceptor compound. In some embodiments, T1 energy of the first host is greater than that of the sensitizer compound. In some embodiments, the sensitizer compound has a HOMO energy that is greater than that of the acceptor compound. In some embodiments, the second host has a HOMO level that is shallower than that of the acceptor compound. In some embodiments, the HOMO level of the acceptor compound is deeper than at least one selected from the sensitizer compound and the first host.
In some embodiments, the first host and/or the second host comprises at least one chemical group selected from the group consisting of triphenylene, carbazole, indolocarbazole, dibenzothiophene, dibenzofuran, dibenzoselenophene, 5λ2-benzo[d]benzo[4,5]imidazo[3,2-a]imidazole, 5,9-dioxa-13b-boranaphtho[3,2,1-de]anthracene, azaborinine, oxaborinine, dihydroacridine, xanthene, dihydrobenzoazasiline, dibenzooxasiline, phenoxazine, phenoxathiine, phenothiazine, dihydrophenazine, fluorene, naphthalene, anthracene, phenanthrene, phenanthroline, benzoquinoline, quinoline, isoquinoline, quinazoline, pyrimidine, pyrazine, pyridine, triazine, boryl, silyl, aza-triphenylene, aza-carbazole, aza-indolocarbazole, aza-dibenzothiophene, aza-dibenzofuran, aza-dibenzoselenophene, aza-5λ2-benzo[d]benzo[4,5]imidazo[3,2-a]imidazole, and aza-(5,9-dioxa-13b-boranaphtho[3,2,1-de]anthracene. In some embodiments the first host and the second host are both organic compounds.
In some embodiments, at least one of the first host and the second host is a metal complex.
In some embodiments, each of the first host and/or the second host is independently selected from the HOST GROUP 1 consisting of:
wherein:
In some embodiments at least one of J1 to J3 are N. In some embodiments at least two of J1 to J3 are N. In some embodiments, all three of J1 to J3 are N. In some embodiments, each YCC and YDD are preferably O, S, and SiRR′, more preferably O, or S. In some embodiments, at least one unsubstituted aromatic carbon atom is replaced with N to form an aza-ring.
To reduce the amount of Dexter energy transfer between the sensitizer compound and the acceptor compound, it would be preferable to have a large distance between the center of mass of the sensitizer compound and the center of mass of the closest neighboring acceptor compound in the emissive region. Therefore, in some embodiments, the distance between the center of mass of the acceptor compound and the center of mass of the sensitizer compound is at least 2, 1.5, 1.0, or 0.75 nm.
Preferred acceptor/sensitizer VDR combination (A): In some embodiments, it is preferable for the VDR of the acceptor to be less than 0.33 in order to reduce the coupling of the transition dipole moment of the emitting acceptor to the plasmon modes, compared to an isotropic emitter, in order to achieve a higher outcoupling efficiency. In some cases, when the VDR of the acceptor is less than 0.33, it would be preferable for the VDR of the sensitizer to be less than 0.33 in order to improve the coupling of the transition dipole moments of the sensitizer and acceptor to optimize the Forster energy transfer rate. Accordingly, in some embodiments of the inventive OLED, the acceptor compound in the inventive OLED exhibits a VDR value equal to or less than 0.33, 0.30, 0.25, 0.2, 0.15, 0.10, 0.08, or 0.05 when the VDR is measured with an emissive thin film test sample that has the acceptor compound as the only emitter; and the sensitizer compound in the inventive OLED exhibits a VDR value equal to or less than 0.33, 0.30, 0.25, 0.2, 0.15, 0.10, 0.08, or 0.05 when the VDR is measured with an emissive thin film test sample that has the sensitizer compound as the only emitter.
Preferred acceptor/sensitizer VDR combination (B): In some embodiments, it is preferable for the VDR of the acceptor to be less than 0.33 in order to reduce the coupling of the transition dipole moment of the emitting acceptor to the plasmon modes compared to an isotropic emitter in order to achieve a higher outcoupling efficiency. In some cases, when the VDR of the acceptor is less than 0.33, it would be preferable to minimize the intermolecular interactions between the sensitizer and acceptor to decrease the degree of Dexter quenching. By changing the molecular geometry of the sensitizer to reduce the intermolecular interactions, it may be preferable to have a sensitizer with a VDR greater than 0.33. Accordingly, in some embodiments of the inventive OLED, the acceptor compound in the inventive OLED exhibits a VDR value equal to or less than 0.33, 0.30, 0.25, 0.2, 0.15, 0.10, 0.08, or 0.05 when the VDR is measured with an emissive thin film test sample that has the acceptor compound as the only emitter; and the sensitizer compound in the inventive OLED exhibits a VDR value larger than 0.33, 0.4, 0.5, 0.6, or 0.7 when the VDR is measured with an emissive thin film test sample that has the sensitizer compound as the only emitter.
Preferred acceptor/sensitizer VDR combination (C): In some embodiments, it is preferable for the VDR of the acceptor to be greater than 0.33 in order to increase the coupling of the transition dipole moment of the acceptor to the plasmon modes compared to an isotropic emitter in order to decrease the transient lifetime of the excited states in the emissive layer. In some cases, the increased coupling to the plasmon modes can be paired with an enhancement layer in a plasmonic OLED device to improve efficiency and extend operational lifetime. In some cases, when the VDR of the acceptor is greater than 0.33, it would be preferable to minimize the intermolecular interactions between the sensitizer and acceptor to decrease the degree of Dexter quenching. By changing the molecular geometry of the sensitizer to reduce the intermolecular interactions, it may be preferable to have a sensitizer with a VDR less than 0.33. Accordingly, in some embodiments of the inventive OLED, the acceptor compound in the inventive OLED exhibits a VDR value larger than 0.33, 0.4, 0.5, 0.6, or 0.7 when the VDR is measured with an emissive thin film test sample that has the acceptor compound as the only emitter; and the sensitizer compound in the inventive OLED exhibits a VDR value equal to or less than 0.33, 0.30, 0.25, 0.2, 0.15, 0.10, 0.08, or 0.05 when the VDR is measured with an emissive thin film test sample that has the sensitizer compound as the only emitter.
Preferred acceptor/sensitizer VDR combination (D): In some embodiments, it is preferable for the VDR of the acceptor to be greater than 0.33 in order to increase the coupling of the transition dipole moment of the acceptor to the plasmon modes compared to an isotropic emitter in order to decrease the transient lifetime of the excited states in the emissive layer. In some cases, the increased coupling to the plasmon modes can be paired with an enhancement layer in a plasmonic OLED device to improve efficiency and extend operational lifetime. In some cases, when the VDR of the acceptor is greater than 0.33, it would be preferable for the VDR of the sensitizer to be greater than 0.33 in order to improve the coupling of the transition dipole moments of the sensitizer and acceptor to optimize the Forster energy transfer rate. Accordingly, in some embodiments of the inventive OLED, the acceptor compound in the inventive OLED exhibits a VDR value larger than 0.33, 0.4, 0.5, 0.6, or 0.7 when the VDR is measured with an emissive thin film test sample that has the acceptor compound as the only emitter; and the sensitizer compound in the inventive OLED exhibits a VDR value larger than 0.33, 0.4, 0.5, 0.6, or 0.7 when the VDR is measured with an emissive thin film test sample that has the sensitizer compound as the only emitter.
VDR is the ensemble average fraction of vertically oriented molecular dipoles of the light-emitting compound in a thin film sample of an emissive layer, where the orientation “vertical” is relative to the plane of the surface of the substrate (i.e., normal to the surface of the substrate plane) on which the thin film sample is formed. A similar concept is horizontal dipole ratio (HDR) which is the ensemble average fraction of horizontally oriented molecular dipoles of the light-emitting compound in a thin film sample of an emissive layer, where the orientation “horizontal” is relative to the plane of the surface of the substrate (i.e. parallel to the surface of the substrate plane) on which the thin film sample is formed. By definition, VDR+HDR=1. VDR can be measured by angle dependent, polarization dependent, photoluminescence measurements. By comparing the measured emission pattern of a photo-excited thin film test sample, as a function of polarization, to the computationally modeled pattern, one can determine VDR of the thin film test sample emission layer. For example, a modelled data of p-polarized emission is shown in
To measure VDR values of the thin film test samples, a thin film test sample can be formed with the acceptor compound or the sensitizer compound (depending on whether the VDR of the acceptor compound or the sensitizer compound is being measured) as the only emitter in the thin film and a Reference Host Compound A as the host. Preferably, the Reference Host Compound A is
The thin film test sample is formed by thermally evaporating the emitter compound and the host compound on a substrate. For example, the emitter compound and the host compound can be co-evaporated. In some embodiments, the doping level of the emitter compounds in the host can be from 0.1 wt. % to 50 wt. %. In some embodiments, the doping level of the emitter compounds in the host can be from 3 wt. % to 20 wt. % for blue emitters. In some embodiments, the doping level of the emitter compounds in the host can be from 1 wt. % to 15 wt. % for red and green emitters. The thickness of the thermally evaporated thin film test sample can have a thickness of from 50 to 1000 Å.
In some embodiments, an OLED such as OLED (1), OLED (2), OLED (3), OLED (4), or OLED (5) as described herein can comprise a sensitizer, an acceptor, and one or more hosts in the emissive region, and the preferred acceptor/sensitizer VDR combinations (A)-(D) mentioned above are still applicable. In these embodiments, the VDR values for the acceptor compound can be measured with a thin film test sample formed of the one or more hosts and the acceptor, where the acceptor is the only emitter in the thin film test sample. Similarly, the VDR values for the sensitizer compound can be measured with a thin film test sample formed of the one or more hosts and the sensitizer, where the sensitizer is the only emitter in the thin film test sample.
In the example used to generate
Because the VDR represents the average dipole orientation of the light-emitting compound in the thin film sample, even if there are additional emission capable compounds in the emissive layer, if they are not contributing to the light emission, the VDR measurement does not reflect their VDR. Further, by inclusion of a host material that interacts with the light-emitting compound, the VDR of the light-emitting compound can be modified. Thus, a light-emitting compound in a thin film sample with host material A will exhibit one measured VDR value and that same light-emitting compound in a thin film sample with host material B will exhibit a different measured VDR value. Further, in some embodiments, exciplex or excimers are desirable which form emissive states between two neighboring molecules. These emissive states may have a VDR that is different than that if only one of the components of the exciplex or excimer were emitting or present in the sample.
In some embodiments, am OLED such as OLED (1), OLED (2), OLED (3), OLED (4), or OLED (5) as described herein may be a plasmonic OLED. In some embodiments, an OLED such as OLED (1), OLED (2), OLED (3), OLED (4), or OLED (5) as described herein may be a wave-guided OLED.
In some embodiments, an OLED such as OLED (1), OLED (2), OLED (3), OLED (4), or OLED (5) as described herein may emit a white light at room temperature when a voltage is applied across the device.
In some embodiments, an OLED such as OLED (1), OLED (2), OLED (3), OLED (4), or OLED (5) as described herein may emit a luminescent radiation at room temperature when a voltage is applied across the device; wherein the luminescent first radiation component contributed from the acceptor compound with an emission λmax1 being independently selected from the group consisting of larger than 340 nm to equal or less than 500 nm, larger than 500 nm to equal or less than 600 nm, and larger than 600 nm to equal or less than 900 nm. In some embodiments, the first radiation component has FWHM of 50, 40, 35, 30, 25, 20, 15, 10, or 5 nm or less. In some embodiments, the first radiation component has a 10% onset of the emission peak is less than 465, 460, 455, or 450 nm.
In some embodiments, the sensitizer compound is partially or fully deuterated. In some embodiments, the acceptor compound is partially or fully deuterated. In some embodiments, the first host is partially or fully deuterated. In some embodiments, the second host is partially or fully deuterated.
In some embodiments, the sensitizer compound and/or the acceptor compound each independently comprises at least one substituent having a spherocity greater than or equal to 0.45, 0.55, 0.65, 0.75, or 0.80. The spherocity is a measurement of the three-dimensionality of bulky groups. Spherocity is defined as the ratio between the principal moments of inertia (PMI). Specifically, spherocity is the ratio of three times PMI1 over the sum of PMI1, PMI2, and PMI3, where PMI1 is the smallest principal moment of inertia, PMI2 is the second smallest principal moment of inertia, and PMI3 is the largest principal moment of inertia. The spherocity of the lowest energy conformer of a structure after optimization of the ground state with density functional theory may be calculated. More detailed information can be found in paragraphs [0054] to [0059] of U.S. application Ser. No. 18/062,110 filed Dec. 6, 2022, the contents of which are incorporated herein by reference. In some embodiments, the sensitizer compound and/or the acceptor compound each independently comprises at least one substituent having a Van der Waals volume greater than 153, 206, 259, 290, or 329 Å3. In some embodiments, compound S1 and/or compound A1 each independently comprises at least one substituent having a molecular weight greater than 167, 187, 259, 303, or 305 amu.
In some embodiments, one of the first and second hosts is a hole transporting host, the other one of the first and second host is an electron transporting host. In some embodiments, the first host is a hole transporting host; and wherein the first host comprises at least one chemical group selected from the group consisting of amino, carbazole, indolocarbazole, dibenzothiophene, dibenzofuran, dibenzoselenophene, and 5λ2-benzo[d]benzo[4,5]imidazo[3,2-a]imidazole. In some embodiments, the first host is an electron transporting host; and wherein the first host comprises at least one chemical group selected from the group consisting of pyridine, pyrimidine, pyrazine, pyridazine, triazine, imidazole, aza-triphenylene, aza-carbazole, aza-dibenzothiophene, aza-dibenzofuran, aza-dibenzoselenophene, 5,9-dioxa-13b-boranaphtho[3,2,1-de]anthracene, boryl, nitrile, aza-5λ2-benzo[d]benzo[4,5]imidazo[3,2-a]imidazole, and aza-(5,9-dioxa-13b-boranaphtho[3,2,1-de]anthracene). In some embodiments, one of the first and second hosts is a bipolar host comprising both hole transporting and electron transporting moieties.
In some embodiments, an OLED such as OLED (1), OLED (2), OLED (3), OLED (4), or OLED (5) as described herein may further comprise a color conversion layer or a color filter.
In some embodiments, a formulation can comprise at least two different compounds of the following compounds: a sensitizer compound, an acceptor compound and a host.
In some embodiments, a chemical structure selected from the group consisting of a monomer, a polymer, a macromolecule, and a supramolecule, wherein the chemical structure comprises at least two of the following components: a sensitizer compound, an acceptor compound and a host.
In some embodiments, a premixed co-evaporation source that is a mixture of a first compound and a second compound; wherein the co-evaporation source is a co-evaporation source for vacuum deposition process or OVJP process; wherein the first compound and the second compound are differently selected from the group 1 consisting of: a sensitizer compound, an acceptor compound, a first host compound; and a second host compound; wherein the first compound has an evaporation temperature T1 of 150 to 350° C.; wherein the second compound has an evaporation temperature T2 of 150 to 350° C.; wherein absolute value of T1-T2 is less than 20° C.; wherein the first compound has a concentration C1 in said mixture and a concentration C2 in a test film formed by evaporating the mixture in a vacuum deposition tool at a constant pressure between 1×10−6 Torr to 1×10−9 Torr, at a 2k/sec deposition rate on a surface positioned at a predefined distance away from the mixture being evaporated; and wherein the absolute value of (C1−C2)/C1 is less than 5%. In some embodiments, the mixture further comprises a third compound; wherein the third compound is different from the first and the second compound, and is selected from the same group 1; wherein the third compound has an evaporation temperature T3 of 150 to 350° C., and wherein absolute value of T1-T3 is less than 20° C.
In some embodiments, the first compound has evaporation temperature T1 of 200 to 350° C. and the second compound has evaporation temperature T2 of 200 to 350° C. In some embodiments, the absolute value of (C1−C2)/C1 is less than 3%. In some embodiments, the first compound has a vapor pressure of P1 at T1 at 1 atm, and the second compound has a vapor pressure of P2 at T2 at 1 atm; and wherein the ratio of P1/P2 is within the range of 0.90:1 to 1.10:1. In some embodiments, the first compound has a first mass loss rate and the second compound has a second mass loss rate, wherein the ratio between the first mass loss rate and the second mass loss rate is within the range of 0.90:1 to 1.10:1, 0.95:1 to 1.05:1, or 0.97:1 to 1.03:1. In some embodiments, the first compound and the second compound each has a purity in excess of 99% as determined by high pressure liquid chromatography. In some embodiments, the composition is in liquid form at a temperature less than the lesser of T1 and T2.
In some embodiments, a method for fabricating an organic light emitting device can comprises: providing a substrate having a first electrode disposed thereon; depositing a first organic layer over the first electrode by evaporating a pre-mixed co-evaporation source that is a mixture of a first compound and a second compound described above in a high vacuum deposition tool with a chamber base pressure between 1×10−6 Torr to 1×10−9 Torr; and depositing a second electrode over the first organic layer.
It should be understood that embodiments of all the compounds and devices described herein may be interchangeable if those embodiments are also applicable under different aspects of the entire disclosure.
In some embodiments, each of the sensitizer compound, the acceptor compound, the host compound, [Add the second acceptor compound A2; and the second host compound H2 if appropriate.] described herein can be at least 10% deuterated, at least 20% deuterated, at least 30% deuterated, at least 40% deuterated, at least 50% deuterated, at least 60% deuterated, at least 70% deuterated, at least 80% deuterated, at least 90% deuterated, at least 95% deuterated, at least 99% deuterated, or 100% deuterated. As used herein, percent deuteration has its ordinary meaning and includes the percent of possible hydrogen atoms (e.g., positions that are hydrogen or deuterium) that are replaced by deuterium atoms.
In some embodiments, an OLED such as OLED (1), OLED (2), OLED (3), OLED (4), or OLED (5) as described herein may further comprise an additional host, wherein the additional host comprises a triphenylene containing benzo-fused thiophene or benzo-fused furan, wherein any substituent in the host is an unfused substituent independently selected from the group consisting of CnH2n+1, OCnH2n+1, OAr1, N(CnH2n+1)2, N(Ar1)(Ar2), CH═CH—CnH2n+1, C≡CCnH2n+1, Ar1, Ar1-Ar2, CnH2n—Ar1, or no substitution, wherein n is an integer from 1 to 10; and wherein Ar1 and Ar2 are independently selected from the group consisting of benzene, biphenyl, naphthalene, triphenylene, carbazole, and heteroaromatic analogs thereof.
In some embodiments, the additional host comprises at least one chemical group selected from the group consisting of triphenylene, carbazole, indolocarbazole, dibenzothiophene, dibenzofuran, dibenzoselenophene, 5λ2-benzo[d]benzo[4,5]imidazo[3,2-a]imidazole, 5,9-dioxa-13b-boranaphtho[3,2,1-de]anthracene, azaborinine, oxaborinine, dihydroacridine, xanthene, dihydrobenzoazasiline, dibenzooxasiline, phenoxazine, phenoxathiine, phenothiazine, dihydrophenazine, fluorene, naphthalene, anthracene, phenanthrene, phenanthroline, benzoquinoline, quinoline, isoquinoline, quinazoline, pyrimidine, pyrazine, pyridine, triazine, boryl, silyl, aza-triphenylene, aza-carbazole, aza-indolocarbazole, aza-dibenzothiophene, aza-dibenzofuran, aza-dibenzoselenophene, aza-5λ2-benzo[d]benzo[4,5]imidazo[3,2-a]imidazole, and aza-(5,9-dioxa-13b-boranaphtho[3,2,1-de]anthracene).
In some embodiments, the additional host comprises a metal complex.
In some embodiments, the additional host is selected from the group consisting of EG1-MG1-EG1 to EG53-MG27-EG53 with a formula of EGa-MGb-EGc, or EG1-EG1 to EG53-EG53 with a formula of EGa-EGc when MGb is absent, wherein a is an integer from 1 to 53, b is an integer from 1 to 27, c is an integer from 1 to 53. The structure of EG1 to EG53 is shown below:
The structure of MG1 to MG27 is shown below:
In the MGb structures shown above, the two bonding positions in the asymmetric structures MG10, MG11, MG12, MG13, MG14, MG17, MG24, and MG25 are labeled with numbers for identification purposes.
In some embodiments, the host can be any of the aza-substituted variants thereof, fully or partially deuterated variants thereof, and combinations thereof. In some embodiments, the host has formula EGa-MGb-Egc and is selected from the group consisting of h1 to h112 defined in the following HOST Group 2 list, where each of MGb, EGa, and EGc are defined as follows:
In the table above, the EGa and EGc structures that are bonded to one of the asymmetric structures MG10, MG11, MG12, MG13, MG14, MG17, MG24, and MG25, are noted with a numeric prefix identifying their bonding position in the MGb structure.
In some embodiments, an emissive region as described herein may consist of one or more organic layers, wherein at least one of the one or more organic layers has a minimum thickness selected from the group consisting of 350, 400, 450, 500, 550, 600, 650 and 700 Å. In some embodiments, the at least one of the one or more organic layers are formed from an Emissive System that has a figure of merit (FOM) value equal to or larger than the number selected from the group consisting of 2.50, 2.55, 2.60, 2.65, 2.70, 2.75, 2.80, 2.85, 2.90, 2.95, 3.00, 5.00, 10.0, 15.0, and 20.0. The definition of FOM is available in U.S. patent Application Publication No. 2023/0292605, and its entire contents are incorporated herein by reference. In some embodiments, the at least one of the one or more organic layers comprises a compound or a formulation of the compound as disclosed in Sections A and D of the present disclosure.
In some embodiments, an OLED such as OLED (1), OLED (2), OLED (3), OLED (4), or OLED (5) as described herein can emit light having at least 1%, 5%, 10, 30%, 50%, 70%, 80%, 90%, 95%, 99%, or 100% from the plasmonic mode. In some embodiments, at least one of the anode, the cathode, or a new layer disposed over the organic emissive layer functions as an enhancement layer. The enhancement layer comprises a plasmonic material exhibiting surface plasmon resonance that non-radiatively couples to the emitter material and transfers excited state energy from the emitter material to non-radiative mode of surface plasmon polariton. In some embodiments, the enhancement layer is provided no more than a threshold distance away from the organic emissive layer, wherein the emitter material has a total non-radiative decay rate constant and a total radiative decay rate constant due to the presence of the enhancement layer. A threshold distance is where the total non-radiative decay rate constant is equal to the total radiative decay rate constant. Another threshold distance is the distance at which the total radiative decay rate constant divided by the sum of the total non-radiative decay rate constant and total radiative decay rate constant is equal to the photoluminescent yield of the emissive material without the enhancement layer present.
In some embodiments, an OLED such as OLED (1), OLED (2), OLED (3), OLED (4), or OLED (5) as described herein further comprises an outcoupling layer. In some embodiments, the outcoupling layer is disposed over the enhancement layer on a side opposite the organic emissive layer The outcoupling layer scatters the energy from the surface plasmon polaritons. In some embodiments this energy is scattered as photons to free space. In other embodiments, the energy is scattered from the surface plasmon mode into other modes of the device such as but not limited to the organic waveguide mode, the substrate mode, or another waveguiding mode. In some embodiments, one or more intervening layer can be disposed between the enhancement layer and the outcoupling layer. The examples for intervening layer(s) can be dielectric materials, including organic, inorganic, perovskites, oxides, and may include stacks and/or mixtures of these materials.
The enhancement layer modifies the effective properties of the medium in which the emitter material resides resulting in any or all of the following: a decreased rate of emission, a modification of emission line-shape, a change in emission intensity with angle, a change in the stability of the emitter material, a change in the efficiency of the OLED, and a reduced efficiency roll-off of the OLED device. Placement of the enhancement layer on the cathode side, anode side, or on both sides, or the enhancement layer itself being as the CGL, results in OLED devices which take advantage of any of the above-mentioned effects. In addition to the specific functional layers mentioned herein and illustrated in the various OLED examples shown in the figures, the OLEDs according to the present disclosure may include any of the other functional layers often found in OLEDs.
In some embodiments, the enhancement layer can be comprised of plasmonic materials, optically active metamaterials, or hyperbolic metamaterials. In some embodiments, the plasmonic material includes at least one metal. In such embodiments the metal may include at least one of Ag, Al, Au, Ir, Pt, Ni, Cu, W, Ta, Fe, Cr, Mg, Ga, Rh, Ti, Ru, Pd, In, Bi, or Ca, alloys or mixtures of these materials, and stacks of these materials. In some embodiments, the enhancement layer is provided as a planar layer. In other embodiments, the enhancement layer has wavelength-sized features that are arranged periodically, quasi-periodically, or randomly, or sub-wavelength-sized features that are arranged periodically, quasi-periodically, or randomly.
In some embodiments, the outcoupling layer has wavelength-sized or sub-wavelength sized features that are arranged periodically, quasi-periodically, or randomly. In some embodiments, the outcoupling layer may be composed of a plurality of nanoparticles. In some embodiments, the outcoupling layer is composed of a plurality of nanoparticles disposed over a material. In these embodiments the outcoupling layer may be tunable by at least one of: varying a size of the plurality of nanoparticles, varying a shape of the plurality of nanoparticles, changing a material of the plurality of nanoparticles, adjusting a thickness of the material, changing the refractive index of the material, adding an additional layer disposed on the plurality of nanoparticles, varying a thickness of the enhancement layer, or varying the material of the enhancement layer. The plurality of nanoparticles of the device may be formed from at least one of metal, dielectric material, semiconductor materials, an alloy of metal, a mixture of dielectric materials, a stack or layering of one or more materials, and/or a core of one type of material and that is coated with a shell of a different type of material. In some embodiments, the outcoupling layer is composed of at least metal nanoparticles wherein the metal is selected from the group consisting of Ag, Al, Au, Ir, Pt, Ni, Cu, W, Ta, Fe, Cr, Mg, Ga, Rh, Ti, Ru, Pd, In, Bi, and Ca, alloys or mixtures of these materials, and stacks of these materials. In some embodiments the outcoupling layer is formed by lithography.
In some embodiments of a plasmonic device, the emitter, and/or host compounds used in the emissive layer has a vertical dipole ratio (VDR) of 0.33 or more. In some such embodiments, the emitter, and/or host compounds have a VDR of 0.40, 0.50, 0.60, 0.70, or more.
Generally, an OLED comprises at least one organic layer disposed between and electrically connected to an anode and a cathode. When a current is applied, the anode injects holes and the cathode injects electrons into the organic layer(s). The injected holes and electrons each migrate toward the oppositely charged electrode. When an electron and hole localize on the same molecule, an “exciton,” which is a localized electron-hole pair having an excited energy state, is formed. Light is emitted when the exciton relaxes via a photoemissive mechanism. In some cases, the exciton may be localized on an excimer or an exciplex. Non-radiative mechanisms, such as thermal relaxation, may also occur, but are generally considered undesirable.
Several OLED materials and configurations are described in U.S. Pat. Nos. 5,844,363, 6,303,238, and 5,707,745, which are incorporated herein by reference in their entirety.
The initial OLEDs used emissive molecules that emitted light from their singlet states (“fluorescence”) as disclosed, for example, in U.S. Pat. No. 4,769,292, which is incorporated by reference in its entirety. Fluorescent emission generally occurs in a time frame of less than 10 nanoseconds.
More recently, OLEDs having emissive materials that emit light from triplet states (“phosphorescence”) have been demonstrated. Baldo et al., “Highly Efficient Phosphorescent Emission from Organic Electroluminescent Devices,” Nature, vol. 395, 151-154, 1998; (“Baldo-I”) and Baldo et al., “Very high-efficiency green organic light-emitting devices based on electrophosphorescence,” Appl. Phys. Lett., vol. 75, No. 3, 4-6 (1999) (“Baldo-II”), are incorporated by reference in their entireties. Phosphorescence is described in more detail in U.S. Pat. No. 7,279,704 at cols. 5-6, which are incorporated by reference.
More examples for each of these layers are available. For example, a flexible and transparent substrate-anode combination is disclosed in U.S. Pat. No. 5,844,363, which is incorporated by reference in its entirety. An example of a p-doped hole transport layer is m-MTDATA doped with F4-TCNQ at a molar ratio of 50:1, as disclosed in U.S. Patent Application Publication No. 2003/0230980, which is incorporated by reference in its entirety. Examples of emissive and host materials are disclosed in U.S. Pat. No. 6,303,238 to Thompson et al., which is incorporated by reference in its entirety. An example of an n-doped electron transport layer is BPhen doped with Li at a molar ratio of 1:1, as disclosed in U.S. Patent Application Publication No. 2003/0230980, which is incorporated by reference in its entirety. U.S. Pat. Nos. 5,703,436 and 5,707,745, which are incorporated by reference in their entireties, disclose examples of cathodes including compound cathodes having a thin layer of metal such as Mg:Ag with an overlying transparent, electrically-conductive, sputter-deposited ITO layer. The theory and use of blocking layers is described in more detail in U.S. Pat. No. 6,097,147 and U.S. Patent Application Publication No. 2003/0230980, which are incorporated by reference in their entireties. Examples of injection layers are provided in U.S. Patent Application Publication No. 2004/0174116, which is incorporated by reference in its entirety. A description of protective layers may be found in U.S. Patent Application Publication No. 2004/0174116, which is incorporated by reference in its entirety.
The simple layered structure illustrated in
Structures and materials not specifically described may also be used, such as OLEDs comprised of polymeric materials (PLEDs) such as disclosed in U.S. Pat. No. 5,247,190 to Friend et al., which is incorporated by reference in its entirety. By way of further example, OLEDs having a single organic layer may be used. OLEDs may be stacked, for example as described in U.S. Pat. No. 5,707,745 to Forrest et al, which is incorporated by reference in its entirety. The OLED structure may deviate from the simple layered structure illustrated in
More details on OLEDs, and the definitions described above, can be found in U.S. Pat. No. 7,279,704, which is incorporated herein by reference in its entirety.
The materials and structures described herein may have applications in devices other than OLEDs. For example, other optoelectronic devices such as organic solar cells and organic photodetectors may employ the materials and structures. More generally, organic devices, such as organic transistors, may employ the materials and structures.
In some embodiments, an OLED such as OLED (1), OLED (2), OLED (3), OLED (4), or OLED (5) as described herein may have one or more characteristics selected from the group consisting of being flexible, being rollable, being foldable, being stretchable, and being curved. In some embodiments, the OLED is transparent or semi-transparent. In some embodiments, the OLED further comprises a layer comprising carbon nanotubes. In some embodiments, an OLED such as OLED (1), OLED (2), OLED (3), OLED (4), or OLED (5) as described herein may further comprise one or more quantum dots. Such quantum dots can be in the emissive layer, or in other functional layers, such as a down conversion layer.
In some embodiments, an OLED such as OLED (1), OLED (2), OLED (3), OLED (4), or OLED (5) as described herein further comprises a layer comprising a delayed fluorescent emitter. In some embodiments, an OLED such as OLED (1), OLED (2), OLED (3), OLED (4), or OLED (5) as described herein comprises a RGB pixel arrangement or white plus color filter pixel arrangement. In some embodiments, an OLED such as OLED (1), OLED (2), OLED (3), OLED (4), or OLED (5) as described herein is a mobile device, a hand held device, or a wearable device. In some embodiments, an OLED such as OLED (1), OLED (2), OLED (3), OLED (4), or OLED (5) as described herein is a display panel having less than 10 inch diagonal or 50 square inch area. In some embodiments, an OLED such as OLED (1), OLED (2), OLED (3), OLED (4), or OLED (5) as described herein is a display panel having at least 10 inch diagonal or 50 square inch area. In some embodiments, an OLED such as OLED (1), OLED (2), OLED (3), OLED (4), or OLED (5) as described herein is a lighting panel.
The materials described herein are as various examples useful for a particular layer in an OLED. They may also be used in combination with a wide variety of other materials present in the device. For example, emissive dopants disclosed herein may be used by themselves in the EML, or in conjunction with a wide variety of other emitters, hosts, transport layers, blocking layers, injection layers, electrodes and other layers that may be present. The materials described or referred to below are non-limiting examples of materials that may be useful in combination with the compounds and the devices disclosed herein, and one of ordinary skill in the art can readily consult the literature to identify other materials that may be useful in combination.
A charge transport layer can be doped with conductivity dopants to substantially alter its density of charge carriers, which will in turn alter its conductivity. The conductivity is increased by generating charge carriers in the matrix material, and depending on the type of dopant, a change in the Fermi level of the semiconductor may also be achieved. Hole-transporting layer can be doped by p-type conductivity dopants and n-type conductivity dopants are used in the electron-transporting layer. In some embodiments, conductivity dopants comprise at least one chemical moiety selected from the group consisting of cyano, fluorinated aryl or heteroaryl, fluorinated alkyl or cycloalkyl, alkylene, heteroaryl, amide, benzodithiophene, and highly conjugated heteroaryl groups extended by non-ring double bonds.
A hole injecting/transporting material to be used in the present disclosure is not particularly limited, and any compound may be used as long as the compound is typically used as a hole injecting/transporting material. Examples of the material include, but are not limited to: a phthalocyanine or porphyrin derivative; an aromatic amine derivative; an indolocarbazole derivative; a polymer containing fluorohydrocarbon; a polymer with conductivity dopants; a conducting polymer, such as PEDOT/PSS; a self-assembly monomer derived from compounds such as phosphonic acid and silane derivatives; a metal oxide derivative, such as MoOx; a p-type semiconducting organic compound, such as 1,4,5,8,9,12-Hexaazatriphenylenehexacarbonitrile; a metal complex, and a cross-linkable compounds.
Examples of aromatic amine derivatives used in HIL or HTL include, but not limit to the following general structures:
Each of Ar1 to Ar9 is selected from the group consisting of aromatic hydrocarbon cyclic compounds such as benzene, biphenyl, triphenyl, triphenylene, naphthalene, anthracene, phenalene, phenanthrene, fluorene, pyrene, chrysene, perylene, and azulene; the group consisting of aromatic heterocyclic compounds such as dibenzothiophene, dibenzofuran, dibenzoselenophene, furan, thiophene, benzofuran, benzothiophene, benzoselenophene, carbazole, indolocarbazole, pyridylindole, pyrrolodipyridine, pyrazole, imidazole, triazole, oxazole, thiazole, oxadiazole, oxatriazole, dioxazole, thiadiazole, pyridine, pyridazine, pyrimidine, pyrazine, triazine, oxazine, oxathiazine, oxadiazine, indole, benzimidazole, indazole, indoxazine, benzoxazole, benzisoxazole, benzothiazole, quinoline, isoquinoline, cinnoline, quinazoline, quinoxaline, naphthyridine, phthalazine, pteridine, xanthene, acridine, phenazine, phenothiazine, phenoxazine, benzofuropyridine, furodipyridine, benzothienopyridine, thienodipyridine, benzoselenophenopyridine, and selenophenodipyridine; and the group consisting of 2 to 10 cyclic structural units which are groups of the same type or different types selected from the aromatic hydrocarbon cyclic group and the aromatic heterocyclic group and are bonded to each other directly or via at least one of oxygen atom, nitrogen atom, sulfur atom, silicon atom, phosphorus atom, boron atom, chain structural unit and the aliphatic cyclic group. Each of Ar1 to Ar9 may be unsubstituted or may be substituted by a general substituent as described above, any two substituents can be joined or fused into a ring.
In some embodiments, each Ar1 to Ar9 independently comprises a moiety selected from the group consisting of:
wherein k is an integer from 1 to 20; X101 to X108 is C or N; Z101 is C, N, O, or S.
Examples of metal complexes used in HIL or HTL include, but are not limited to the following general formula:
wherein Met is a metal, which can have an atomic weight greater than 40; (Y101-Y102) is a bidentate ligand, the coordinating atoms of Y101 and Y102 are independently selected from C, N, O, P, and S; L101 is an another ligand; k′ is an integer value from 1 to the maximum number of ligands that may be attached to the metal; and k′+k″ is the maximum number of ligands that may be attached to the metal.
In some embodiments, (Y101-Y102) is a 2-phenylpyridine or 2-phenylimidazole derivative. In some embodiments, (Y101-Y102) is a carbene ligand. In some embodiments, Met is selected from Ir, Pt, Pd, Os, Cu, and Zn. In some embodiments, the metal complex has a smallest oxidation potential in solution vs. Fc+/Fc couple less than about 0.6 V.
In some embodiments, the HIL/HTL material is selected from the group consisting of phthalocyanine and porphryin compounds, starburst triarylamines, CFx fluorohydrocarbon polymer, conducting polymers (e.g., PEDOT:PSS, polyaniline, polypthiophene), phosphonic acid and silane SAMs, triarylamine or polythiophene polymers with conductivity dopants, Organic compounds with conductive inorganic compounds (such as molybdenum and tungsten oxides), n-type semiconducting organic complexes, metal organometallic complexes, cross-linkable compounds, polythiophene based polymers and copolymers, triarylamines, triaylamine with spirofluorene core, arylamine carbazole compounds, triarylamine with (di)benzothiophene/(di)benzofuran, indolocarbazoles, isoindole compounds, and metal carbene complexes.
An electron blocking layer (EBL) may be used to reduce the number of electrons and/or excitons that leave the emissive layer. The presence of such a blocking layer in a device may result in substantially higher efficiencies, and/or longer lifetime, as compared to a similar device lacking a blocking layer. Also, a blocking layer may be used to confine emission to a desired region of an OLED. In some embodiments, the EBL material has a higher LUMO (closer to the vacuum level) and/or higher triplet energy than one or more emitters closest to the EBL interface. In some embodiments, the compound used in EBL contains at least one carbazole group and/or at least one arylamine group. In some embodiments the HOMO level of the compound used in the EBL is shallower than the HOMO level of one or more of the hosts in the EML. In some embodiments, the compound used in EBL contains the same molecule or the same functional groups used as one of the hosts described herein.
The light emitting layer of the organic EL device of the present disclosure preferably contains at least a light emitting material as the dopant, and a host material. Examples of the host material are not particularly limited, and any metal complexes or organic compounds may be used as long as the host won't fully quench the emission of the dopant.
Examples of metal complexes used as host are preferred to have the following general formula:
wherein Met is a metal; (Y103-Y104) is a bidentate ligand, the coordinating atoms of Y103 and Y104 are independently selected from C, N, O, P, and S; L101 is an another ligand; k′ is an integer value from 1 to the maximum number of ligands that may be attached to the metal; and k′+k″ is the maximum number of ligands that may be attached to the metal.
In some embodiments, the metal complexes are:
wherein (O—N) is a bidentate ligand, having metal coordinated to atoms O and N.
In some embodiments, Met is selected from Ir and Pt. In a further embodiment, (Y103-Y104) is a carbene ligand.
In some embodiments, the host compound contains at least one of the following groups selected from the group consisting of aromatic hydrocarbon cyclic compounds such as benzene, biphenyl, triphenyl, triphenylene, tetraphenylene, naphthalene, anthracene, phenalene, phenanthrene, fluorene, pyrene, chrysene, perylene, and azulene; the group consisting of aromatic heterocyclic compounds such as dibenzothiophene, dibenzofuran, dibenzoselenophene, furan, thiophene, benzofuran, benzothiophene, benzoselenophene, carbazole, indolocarbazole, pyridylindole, pyrrolodipyridine, pyrazole, imidazole, triazole, oxazole, thiazole, oxadiazole, oxatriazole, dioxazole, thiadiazole, pyridine, pyridazine, pyrimidine, pyrazine, triazine, oxazine, oxathiazine, oxadiazine, indole, benzimidazole, indazole, indoxazine, benzoxazole, benzisoxazole, benzothiazole, quinoline, isoquinoline, cinnoline, quinazoline, quinoxaline, naphthyridine, phthalazine, pteridine, xanthene, acridine, phenazine, phenothiazine, phenoxazine, aza-dibenzothiophene, aza-dibenzofuran, aza-dibenzoselenophene, aza-carbazole, aza-indolocarbazole, aza-triphenylene, aza-tetraphenylene, 5λ2-benzo[d]benzo[4,5]imidazo[3,2-a]imidazole, 5,9-dioxa-13b-boranaphtho[3,2,1-de]anthracene; and the group consisting of 2 to 10 cyclic structural units which are groups of the same type or different types selected from the aromatic hydrocarbon cyclic group and the aromatic heterocyclic group and are bonded to each other directly or via at least one of oxygen atom, nitrogen atom, sulfur atom, silicon atom, phosphorus atom, boron atom, chain structural unit and the aliphatic cyclic group. Each option within each group may be unsubstituted or may be substituted by the general substituents as described herein or may be further fused.
In some embodiments, the host compound comprises at least one of the moieties selected from the group consisting of:
wherein k is an integer from 0 to 20 or 1 to 20. X101 to X108 are independently selected from C or N. Z101 and Z102 are independently selected from C, N, O, or S.
In some embodiments, the host material is selected from the group consisting of arylcarbazoles, metal 8-hydroxyquinolates, (e.g., alq3, balq), metal phenoxybenzothiazole compounds, conjugated oligomers and polymers (e.g., polyfluorene), aromatic fused rings, zinc complexes, chrysene based compounds, aryltriphenylene compounds, poly-fused heteroaryl compounds, donor acceptor type molecules, dibenzofuran/dibenzothiophene compounds, polymers (e.g., pvk), spirofluorene compounds, spirofluorene-carbazole compounds, indolocabazoles, 5-member ring electron deficient heterocycles (e.g., triazole, oxadiazole), tetraphenylene complexes, metal phenoxypyridine compounds, metal coordination complexes (e.g., Zn, Al with NAN ligands), dibenzothiophene/dibenzofuran-carbazole compounds, silicon/germanium aryl compounds, aryl benzoyl esters, carbazole linked by non-conjugated groups, aza-carbazole/dibenzofuran/dibenzothiophene compounds, and high triplet metal organometallic complexes (e.g., metal-carbene complexes).
One or more additional emitter materials may be used in conjunction with the compound or device of the present disclosure. The one or more additional emitter materials can be emissive or non-emissive in the current device as described herein. For example, an additional emitter material that is a phosphorescent material can be used in an OLED device to provide a sensitizer function, and that same phosphorescent material can also be used in that OLED device as a light emitting phosphorescent emitter in another layer. Examples of the emitter materials are not particularly limited, and any compounds may be used as long as the compounds are capable of producing emissions in a regular OLED device. Examples of suitable additional emitter materials include, but are not limited to, compounds which are capable of producing emissions via phosphorescence, non-delayed fluorescence, delayed fluorescence, especially the thermally activated delayed fluorescence, i.e., TADF (also referred to as E-type delayed fluorescence), triplet-triplet annihilation, or combinations of these processes. Each of these materials suitable for the additional emitter materials has been described in the previous sections.
A hole blocking layer (HBL) may be used to reduce the number of holes and/or excitons that leave the emissive layer. The presence of such a blocking layer in a device may result in substantially higher efficiencies and/or longer lifetime as compared to a similar device lacking a blocking layer. Also, a blocking layer may be used to confine emission to a desired region of an OLED. In some embodiments, the HBL material has a lower HOMO (further away from the vacuum level) and/or higher triplet energy than one or more of the emitters closest to the HBL interface.
In some embodiments, a compound used in the HBL contains the same molecule or the same functional groups used as host described above.
In some embodiments, a compound used in the HBL comprises at least one of the following moieties selected from the group consisting of:
wherein k is an integer from 1 to 20; L101 is another ligand, k′ is an integer from 1 to 3.
Electron transport layer (ETL) may include a material capable of transporting electrons. Electron transport layer may be intrinsic (undoped), or doped. Doping may be used to enhance conductivity. Examples of the ETL material are not particularly limited, and any metal complexes or organic compounds may be used as long as they are typically used to transport electrons.
In some embodiments, compound used in ETL comprises at least one of the following moieties in the molecule:
and fullerenes; wherein k is an integer from 1 to 20, X101 to X108 is selected from C or N; Z101 is selected from the group consisting of C, N, O, and S.
In some embodiments, the metal complexes used in ETL contains, but not limit to the following general formula:
wherein (O—N) or (N—N) is a bidentate ligand, having metal coordinated to atoms O, N or N, N; L101 is another ligand; k′ is an integer value from 1 to the maximum number of ligands that may be attached to the metal.
In some embodiments, the ETL material is selected from the group consisting of anthracene-benzoimidazole compounds, aza triphenylene derivatives, anthracene-benzothiazole compounds, metal 8-hydroxyquinolates, metal hydroxybenoquinolates, bathocuprine compounds, 5-member ring electron deficient heterocycles (e.g., triazole, oxadiazole, imidazole, benzoimidazole), silole compounds, arylborane compounds, fluorinated aromatic compounds, fullerene (e.g., C60), triazine complexes, and Zn (N{circumflex over ( )}N) complexes.
In tandem or stacked OLEDs, the CGL plays an essential role in the performance, which is composed of an n-doped layer and a p-doped layer for injection of electrons and holes, respectively. Electrons and holes are supplied from the CGL and electrodes. The consumed electrons and holes in the CGL are refilled by the electrons and holes injected from the cathode and anode, respectively; then, the bipolar currents reach a steady state gradually. Typical CGL materials include n and p conductivity dopants used in the transport layers.
In any compounds disclosed herein, the hydrogen atoms can be partially or fully deuterated. The minimum amount of hydrogen of the compound being deuterated is selected from the group consisting of 30%, 40%, 50%, 60%, 70%, 80%, 90%, 95%, 99%, and 100%. As used herein, percent deuteration has its ordinary meaning and includes the percent of all possible hydrogen and deuterium atoms that are replaced by deuterium atoms. In some embodiments, the deuterium atoms are attached to an aromatic ring. In some embodiments, the deuterium atoms are attached to a saturated carbon atom, such as an alkyl or cycloalkyl carbon atom. In some other embodiments, the deuterium atoms are attached to a heteroatom, such as Si, or Ge atom.
It is understood that the various embodiments described herein are by way of example only and are not intended to limit the scope of the present disclosure. For example, many of the materials and structures described herein may be substituted with other materials and structures without deviating from the spirit of the present disclosure. The present invention as claimed may therefore include variations from the particular examples and preferred embodiments described herein, as will be apparent to one of skill in the art. It is understood that various theories as to why the invention works are not intended to be limiting.
It should also be understood that embodiments of all the compounds and devices described herein may be interchangeable if those embodiments are also applicable under different aspects of the entire disclosure.
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In a brief summary of all the above figures, in any given configuration/stack above, or otherwise described herein, an ER11′ emissive region can be or comprise any emissive region with an identified color, and an ER21′ emissive region can be or comprise any other emissive region with an identified color so long as the ER11′ emissive region is separated from the ER21′ emissive region by one or more CGLs in a configuration. Any remaining emissive regions such as ER31′ and/or ER41′ with an identified color may or may not include any additional sensitizer/acceptor pair. It should also be understood that even though the term “emissive region” is used for all the above configurations (e.g., those with one or more emissive layers), an emissive region may also represent an “emissive layer” when there is only one emissive layer within that region. In such embodiments, the term “an emissive region” is intended to be interchangeable with “an emissive layer”.
This application is a continuation-in-part of co-pending U.S. patent application Ser. No. 18/491,112, filed on Oct. 20, 2023, which is a continuation-in-part of co-pending U.S. patent application Ser. No. 18/319,182, filed May 17, 2023. The application Ser. No. 18/491,112 also claims priority under 35 U.S.C. § 119(e) to U.S. Provisional Applications No. 63/419,782, filed on Oct. 27, 2022, No. 63/421,804, filed Nov. 2, 2022, No. 63/387,166, filed Dec. 13, 2022, No. 63/483,647, filed Feb. 7, 2023, No. 63/487,055, filed Feb. 27, 2023, No. 63/459,091, filed Apr. 13, 2023, No. 63/434,161, filed Dec. 21, 2022, No. 63/484,757, filed Feb. 14, 2023, No. 63/484,786, filed Feb. 14, 2023, and No. 63/490,065, filed Mar. 14, 2023. This application is also a continuation-in-part of co-pending U.S. patent application Ser. No. 18/491,028, filed on Oct. 20, 2023, which is a continuation-in-part of co-pending U.S. patent application Ser. No. 18/319,182, filed May 17, 2023. The application Ser. No. 18/491,028 also claims priority under 35 U.S.C. § 119(e) to U.S. Provisional Applications No. 63/419,782, filed on Oct. 27, 2022, No. 63/421,804, filed Nov. 2, 2022, No. 63/387,166, filed Dec. 13, 2022, No. 63/483,647, filed Feb. 7, 2023, No. 63/487,055, filed Feb. 27, 2023, No. 63/459,091, filed Apr. 13, 2023, No. 63/434,161, filed Dec. 21, 2022, No. 63/484,757, filed Feb. 14, 2023, No. 63/484,786, filed Feb. 14, 2023, and No. 63/490,065, filed Mar. 14, 2023. The entire contents of all the above referenced applications are incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 63419782 | Oct 2022 | US | |
| 63421804 | Nov 2022 | US | |
| 63387166 | Dec 2022 | US | |
| 63483647 | Feb 2023 | US | |
| 63487055 | Feb 2023 | US | |
| 63459091 | Apr 2023 | US | |
| 63434161 | Dec 2022 | US | |
| 63484757 | Feb 2023 | US | |
| 63484786 | Feb 2023 | US | |
| 63490065 | Mar 2023 | US | |
| 63419782 | Oct 2022 | US | |
| 63421804 | Nov 2022 | US | |
| 63387166 | Dec 2022 | US | |
| 63483647 | Feb 2023 | US | |
| 63487055 | Feb 2023 | US | |
| 63459091 | Apr 2023 | US | |
| 63434161 | Dec 2022 | US | |
| 63484757 | Feb 2023 | US | |
| 63484786 | Feb 2023 | US | |
| 63490065 | Mar 2023 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 18491112 | Oct 2023 | US |
| Child | 19072265 | US | |
| Parent | 18319182 | May 2023 | US |
| Child | 18491112 | US | |
| Parent | 18491028 | Oct 2023 | US |
| Child | 19072265 | US | |
| Parent | 18319182 | May 2023 | US |
| Child | 18491028 | US |
