Patent Application
20230320116
This application claims priority to and the benefit of Korean Patent Application No. 10-2022-0041192, filed on Apr. 1, 2022, in the Korean Intellectual Property Office, the entire content of which is incorporated herein by reference.
One or more aspects of embodiments of the present disclosure relate to a method of preparing a quantum dot, a quantum dot, and a light-emitting device, an optical member, and an apparatus that include the quantum dot.
Quantum dots are nanocrystals of semiconductor materials and exhibit a quantum confinement effect. When quantum dots reach an energy excited state by receiving light from an excitation source, they emit energy according to a corresponding energy band gap by themselves. In this regard, even in the same material, the wavelength varies depending on the particle size, and accordingly, by adjusting the size of quantum dots, light having a desired or suitable wavelength range may be obtained, and excellent or improved color purity and high luminescence efficiency may be obtained. Thus, quantum dots are applicable to various devices.
In addition, a quantum dot can be used as a material that performs various optical functions (for example, a photo-conversion function) in optical members. Quantum dots, as nano-sized semiconductor nanocrystals, may have different energy band gaps by adjusting the size and composition of the nanocrystals, and thus may emit light of various emission wavelengths.
An optical member including such quantum dots may have the form of a thin film, for example, a thin film patterned for each subpixel. Such an optical member may be used as a color-conversion member of a device including various light sources.
One or more aspects of embodiments of the present disclosure include a method of preparing a quantum dot, the method being capable of controlling an energy level of a quantum dot, a quantum dot having a controlled energy level, and a light-emitting device, an optical member, and an apparatus that include the quantum dot.
Additional aspects will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the presented embodiments of the disclosure.
According to one or more embodiments, provided is a method of preparing a quantum dot, the method including:
According to one or more embodiments, provided is a quantum dot prepared by the method.
According to one or more embodiments, provided is a light-emitting device including a first electrode, a second electrode facing the first electrode, and an emission layer arranged between the first electrode and the second electrode, wherein the emission layer includes the quantum dot.
According to one or more embodiments, provided is an optical member including the quantum dot.
According to one or more embodiments, provided is an apparatus including the quantum dot.
The above and other aspects, features, and advantages of certain embodiments of the disclosure will be more apparent from the following description taken in conjunction with the accompanying drawings, in which:
Reference will now be made in more detail to embodiments, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. In this regard, the present embodiments may have different forms and should not be construed as being limited to the descriptions set forth herein. Accordingly, the embodiments are merely described below, by referring to the figures, to explain aspects of the present description. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. Throughout the disclosure, the expressions such as “at least one of”, “one of”, and “selected from”, when preceding a list of elements, modify the entire list of elements and do not modify the individual elements of the list. For example, the expression “at least one of a, b or c” indicates only a, only b, only c, both a and b, both a and c, both b and c, all of a, b, and c, or variations thereof.
Further, the use of “may” when describing embodiments of the present disclosure refers to “one or more embodiments of the present disclosure”.
Because the disclosure may have diverse modified embodiments, embodiments are illustrated in the drawings and are described in the detailed description. An effect and a characteristic of the disclosure, and a method of accomplishing these will be apparent when referring to embodiments described with reference to the drawings. The disclosure may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.
Hereinafter, embodiments of the disclosure will be described in more detail with reference to the accompanying drawings. The same or corresponding components will be denoted by the same reference numerals, and thus redundant description thereof will not be provided.
It will be understood that although the terms “first,” “second,” etc. may be used herein to describe various components, these components should not be limited by these terms. These components are only used to distinguish one component from another.
An expression used in the singular encompasses the expression of the plural, unless it has a clearly different meaning in the context.
It will be further understood that the terms “comprises” and/or “comprising” used herein specify the presence of stated features or elements, but do not preclude the presence or addition of one or more other features or elements.
In the following embodiments, when various components such as layers, films, regions, plates, etc. are said to be “on” another component, this may include not only a case in which other components are “immediately on” or “directly on” the layers, films, regions, or plates (e.g., without any intervening components therebetween), but also a case in which other components may be placed therebetween. Sizes of elements in the drawings may be exaggerated for convenience of explanation. In other words, because sizes and thicknesses of components in the drawings are arbitrarily illustrated for convenience of explanation, the following embodiments are not limited thereto.
Spatially relative terms, such as “beneath,” “below,” “lower,” “above,” “upper,” “bottom,” “top” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” or “over” the other elements or features. Thus, the term “below” may encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations), and the spatially relative descriptors used herein should be interpreted accordingly.
As used herein, the terms “substantially”, “about”, and similar terms are used as terms of approximation and not as terms of degree, and are intended to account for the inherent deviations in measured or calculated values that would be recognized by those of ordinary skill in the art. “About” or “approximately,” as used herein, is inclusive of the stated value and means within an acceptable range of deviation for the particular value as determined by one of ordinary skill in the art, considering the measurement in question and the error associated with measurement of the particular quantity (i.e., the limitations of the measurement system). For example, “about” may mean within one or more standard deviations, or within ±30%, 20%, 10%, 5% of the stated value.
Any numerical range recited herein is intended to include all sub-ranges of the same numerical precision subsumed within the recited range. For example, a range of “1.0 to 10.0” is intended to include all subranges between (and including) the recited minimum value of 1.0 and the recited maximum value of 10.0, that is, having a minimum value equal to or greater than 1.0 and a maximum value equal to or less than 10.0, such as, for example, 2.4 to 7.6. Any maximum numerical limitation recited herein is intended to include all lower numerical limitations subsumed therein and any minimum numerical limitation recited in this specification is intended to include all higher numerical limitations subsumed therein. Accordingly, Applicant reserves the right to amend this specification, including the claims, to expressly recite any sub-range subsumed within the ranges expressly recited herein.
The electronic device and/or any other relevant devices or components according to embodiments of the present invention described herein may be implemented utilizing any suitable hardware, firmware (e.g. an application-specific integrated circuit), software, or a combination of software, firmware, and hardware. For example, the various components of the apparatus may be formed on one integrated circuit (IC) chip or on separate IC chips. Further, the various components of the apparatus may be implemented on a flexible printed circuit film, a tape carrier package (TCP), a printed circuit board (PCB), or formed on one substrate. Further, the various components of the apparatus may be a process or thread, running on one or more processors, in one or more computing devices, executing computer program instructions and interacting with other system components for performing the various functionalities described herein. The computer program instructions are stored in a memory which may be implemented in a computing device using a standard memory device, such as, for example, a random access memory (RAM). The computer program instructions may also be stored in other non-transitory computer readable media such as, for example, a CD-ROM, flash drive, or the like. Also, a person of skill in the art should recognize that the functionality of various computing devices may be combined or integrated into a single computing device, or the functionality of a particular computing device may be distributed across one or more other computing devices without departing from the scope of the embodiments of the present disclosure.
Referring to
Forming a first mixture including a core, a zinc-containing first material, and a selenium-containing second material (S110);
In addition, with respect to a volume of the zinc-containing third material in the fourth mixture, a volume ratio of the ligand precursor to the total volume of the fifth mixture may be in a range of about 0.01 to about 1.0, for example, about 0.05 to about 0.8, or about 0.06 to about 0.7. By satisfying any of the numerical ranges as described above, a light-emitting device including the quantum dot according to one or more embodiments may have improved quantum dot efficiency (EQE) and a long lifespan.
In addition, with respect to the volume of the zinc-containing third material in the fourth mixture, the volume ratio of the ligand precursor to the total volume of the fifth mixture may be measured, wherein the third material may be a zinc (Zn) stock solution, and a concentration of the Zn stock solution may be about 0.5 M.
In addition, with respect to the volume of the zinc-containing third material in the fourth mixture, the volume ratio of the ligand precursor to the total volume of the fifth mixture may be measured, wherein the ligand precursor may be a hydrogen fluoride (HF) solution, and the HF solution may be a solution in which trioctylamine (TOA) and HF are mixed at a volume ratio in a range of about 8:1 to about 10:1.
The method of preparing the quantum dot according to one or more embodiments may further include forming a core comprising a Group II-VI compound, from a Group II precursor and a Group VI precursor.
In the method of preparing the quantum dot according to one or more embodiments, the core may include ZnSeTe, and a concentration gradient in which an amount of selenium (Se) increases as it approaches the first shell may be formed.
In the method of preparing the quantum dot according to one or more embodiments, each of the first material and the third material may include zinc acetate.
In the method of preparing the quantum dot according to one or more embodiments, the second material may include selenium powder, and the fourth material may include sulfur powder.
In the method of preparing the quantum dot according to one or more embodiments, the first and second tasks or steps (S110 and S120) may be performed at the same concentration.
In the method of preparing the quantum dot according to one or more embodiments, the forming of the ligand layer may be performed at a temperature lower than a temperature at which the forming of the fourth mixture is performed.
In the method of preparing the quantum dot according to one or more embodiments, the forming of the ligand layer may be performed under a temperature-raising condition.
In the method of preparing the quantum dot according to one or more embodiments, a starting temperature of the temperature-raising condition may be about 150° C., and a maximum temperature may be about 270° C.
In the method of preparing the quantum dot according to one or more embodiments, the ligand layer may cover a portion or all of the second shell.
In the method of preparing the quantum dot according to one or more embodiments, a ligand derived from the ligand precursor may have polarity.
In the method of preparing the quantum dot according to one or more embodiments, the ligand may be chemically bonded to the second shell, or may form a coordinate bond with the second shell.
In the method of preparing the quantum dot according to one or more embodiments, the ligand may be derived from one or more compounds selected from a thiol-based compound, an amine-based compound, an oxide-based compound, a phosphine-based compound, and a halide-based compound.
In the method of preparing the quantum dot according to one or more embodiments, a formal charge of the ligand may be positive, negative, or neutral.
In the method of preparing the quantum dot according to one or more embodiments, the ligand may include one or more electron-donating groups, and a shared electron pair or an unshared electron pair of the ligand may be shared or coordinated with the second shell.
In the method of preparing the quantum dot according to one or more embodiments, the ligand may include one or more electron-withdrawing groups, and a shared electron pair or an unshared electron pair of the ligand may be shared or coordinated with the second shell.
In the method of preparing the quantum dot according to one or more embodiments, the ligand may change magnitude of a dipole momentum of the second shell. For example, by the ligand, the magnitude of the dipole momentum of the second shell may increase or decrease.
In the method of preparing the quantum dot according to one or more embodiments, a main chain of the ligand may include one or more of a C1-C60 alkyl group, a C2-C60 alkenyl group, a C2-C60 alkynyl group, a C3-C10 cycloalkyl group, or a C6-C60 aryl group, and may satisfy one or more selected from the following conditions:
In the method of preparing the quantum dot according to one or more embodiments, the fifth material may further include, in addition to a halide ion, one or more selected from a sodium ion (Na+), a potassium ion (K+), a magnesium ion (Mg2+), a calcium ion (Ca2+), and a zinc ion (Zn2+), and the ligand may include the halide ion.
In the method of preparing the quantum dot according to one or more embodiments, the fifth material may be in a powder form.
In the method of preparing the quantum dot according to one or more embodiments, with respect to a surface area of the second shell, the fifth material may be included in a range of about 0.1 g/nm2 to about 1 g/nm2.
One or more embodiments of the disclosure provide a quantum dot prepared by any one of the methods of preparing the quantum dot according to one or more embodiments.
In one or more embodiments, the present disclosure provides a quantum dot including: a core including a first Group II-VI compound; a first shell covering the core and including a second Group II-VI compound; a second shell covering the first shell and including a third Group II-VI compound; and a ligand layer covering the second shell and including a ligand, wherein the ligand is chemically bonded to at least a portion of the second shell, and with respect to a surface area of the second shell, the number of moles of the ligand is in a range of about 0.2 mol/nm2 to about 2 mol/nm2.
The first Group II-VI compound, the second Group II-VI compound, and the third Group II-VI compound may each independently be selected from the group consisting of: binary compounds selected from CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, and mixtures thereof; ternary compounds selected from CdSeS, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, and mixtures thereof; and quaternary compounds selected from CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, HgZnSTe, and mixtures thereof.
In some embodiments, the first Group II-VI compound may be a ternary compound, and may be, for example, ZnSeTe.
In some embodiments, the second Group II-VI compound may be a binary compound, and may be, for example, ZnSe.
In some embodiments, the third Group II-VI compound may be a binary compound, and may be, for example, ZnS.
The core, the first shell, and the second shell may have a structure in which a combination of each shell forms a concentration gradient and a lattice mismatch is reduced. Therefore, the occurrence of defects at the interface between the core and the shell may be reduced, the core of the quantum dot may be protected by using a sufficiently or suitably thick shell, and high luminescence efficiency and high color purity may be simultaneously or concurrently realized.
In one or more embodiments, a form of the quantum dot is not particularly limited, and may be any suitable form in the art.
For example, the quantum dot may be a spherical, pyramidal, multi-arm, and/or cubic nanoparticle, nanotube, nanowire, nanofiber, and/or nanoplate particle.
In one or more embodiments, the quantum dot may further include a compound other than the above-described composition.
For example, the quantum dot may further include, in the core, the first shell, and the second shell, a Group III-VI compound, a Group III-V compound, a Group IV-VI compound, a Group IV element or compound, a Group I-III-VI compound, or a combination thereof.
The Group III-VI compound may include: a binary compound, such as In2S3 and/or In2Se; a ternary compound, such as InGaS3 and/or InGaSe3; or any combination thereof.
The Group III-V compound may be selected from: binary compounds selected from GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, and mixtures thereof; ternary compounds selected from GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InGaP, InAlP, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, and mixtures thereof; and quaternary compounds selected from GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, InAlPSb, and mixtures thereof.
The Group IV-VI compound may be selected from: binary compounds selected from SnS, SnSe, SnTe, PbS, PbSe, PbTe, and mixtures thereof; ternary compounds selected from SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, and mixtures thereof; and quaternary compounds selected from SnPbSSe, SnPbSeTe, SnPbSTe, and mixtures thereof.
The Group I-III-VI compound may include: a ternary compound, such as AgInS, AgInS2, CuInS, CuInS2, CuGaO2, AgGaO2, AgAlO2, and/or the like; or any combination thereof.
The binary compound, the ternary compound, or the quaternary compound may exist in particles at uniform (or substantially uniform) concentration, or may exist in the same particle in a state in which a concentration distribution is partially different.
The term “quantum dot” as used herein refers to a crystal of a semiconductor compound, and may include any suitable material capable of emitting light of various emission wavelengths according to the size of the crystal.
A diameter of the quantum dot may be, for example, in a range of about 1 nm to about 10 nm.
As used herein, unless otherwise defined, a diameter (e.g., an average particle diameter (D50)) refers to a diameter of particles having a cumulative volume of 50% by volume in the particle size distribution. The average particle size D50 may be measured by a suitable technique, e.g., using a particle size analyzer, transmission electron microscope photography, and/or scanning electron microscope photography. Another method may be performed by using a measuring device with dynamic light scattering, analyzing data to count a number of particles relative to each particle size, and then calculating to obtain an average particle diameter D50. Also, when particles are spherical, “diameter” indicates a spherical particle diameter or an average particle diameter, and when the particles are non-spherical, the “diameter” indicates a major axis length or an average major axis length.
In the quantum dot according to one or more embodiments, an average diameter of the core may be in a range of about 3 nm to about 8 nm.
In the quantum dot according to one or more embodiments, an average thickness of the first shell may be smaller than a thickness of the core.
In the quantum dot according to one or more embodiments, an average thickness of the first shell may be in a range of about 1 nm to about 4 nm.
In the quantum dot according to one or more embodiments, an average thickness of the second shell may be smaller than that of the first shell.
In the quantum dot according to one or more embodiments, an average thickness of the second shell may be in a range of about 0.5 nm to about 1.5 nm.
The quantum dot may be synthesized by a wet chemical process, a metal organic chemical vapor deposition process, a molecular beam epitaxy process, or any process similar thereto.
The wet chemical process is a method including mixing a precursor material with an organic solvent and then growing quantum dot particle crystals. When the crystal grows, the organic solvent naturally acts as a dispersant coordinated on the surface of the quantum dot crystal and controls the growth of the crystal so that the growth of quantum dot particles can be controlled through a process which costs less, and is easier than vapor deposition methods, such as metal organic chemical vapor deposition (MOCVD) and/or molecular beam epitaxy (MBE).
The quantum dot may have a full width of half maximum (FWHM) of an emission wavelength spectrum of less than or equal to about 45 nm, less than or equal to about 40 nm, or for example, less than or equal to about 30 nm. When the FWHM of the quantum dot is within any of these ranges, the quantum dot may have improved color purity and/or improved color reproducibility. In addition, because light emitted through the quantum dot is emitted in all directions, the wide viewing angle may be improved.
Because the energy band gap may be adjusted by controlling the size of the quantum dot, light having various wavelength bands may be obtained from the quantum dot emission layer. Accordingly, by using quantum dot of different sizes, a light-emitting device that emits light of various wavelengths may be implemented. In one or more embodiments, the size (e.g., diameter or major axis length) of the quantum dot may be selected to emit red light, green light, and/or blue light, and for example, types (or kinds) and amounts of the ligand may be adjusted to emit blue light.
In addition, the size of the quantum dot may be configured to emit white light by combination of light of various colors.
By the method of preparing the quantum dot according to the present disclosure, the energy level of the quantum dot may be further lowered or increased, the adjustment of the energy level of the quantum dot may be performed precisely and easily (e.g., suitably), and the quantum dot emitting blue light may be prepared in a high (e.g., increased) yield.
In addition, by adjusting the amount of the ligand bonded to the quantum dot, the efficiency of hole transport and electron transport may be increased, and furthermore, the luminescence efficiency may be improved by the quantum dot. Furthermore, a device, an optical member, and an apparatus that include the quantum dot may have improved efficiency and long lifespan.
Hereinafter, a structure of the light-emitting device 30 according to one or more embodiments and a method of manufacturing the light-emitting device 30 will be described with reference to
The interlayer or the emission layer may include the quantum dot.
In
The first electrode 110 may be formed by, for example, depositing or sputtering a material for forming the first electrode 110 on the substrate. When the first electrode 110 is an anode, a material for forming the first electrode 110 may be a high-work function material that facilitates injection of holes.
The first electrode 110 may be a reflective electrode, a semi-transmissive electrode, or a transmissive electrode. In one or more embodiments, when the first electrode 110 is a transmissive electrode, a material for forming the first electrode 110 may include indium tin oxide (ITO), indium zinc oxide (IZO), tin oxide (SnO2), zinc oxide (ZnO), or any combination thereof. In one or more embodiments, when the first electrode 110 is a semi-transmissive electrode or a reflective electrode, a material for forming the first electrode 110 may include magnesium (Mg), silver (Ag), aluminum (Al), aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In), magnesium-silver (Mg—Ag), or any combination thereof.
The first electrode 110 may have a single-layered structure including (e.g., consisting of) a single layer or a multi-layered structure including multiple layers. For example, the first electrode 110 may have a three-layered structure of ITO/Ag/ITO.
The interlayer 130 is arranged on the first electrode 110. The interlayer 130 may include an emission layer.
The interlayer 130 may further include a hole transport region arranged between the first electrode 110 and the emission layer, and an electron transport region arranged between the emission layer and the second electrode 150.
In one or more embodiments, the interlayer 130 may further include, in addition to various organic materials, a metal-containing compound such as an organometallic compound, an inorganic material such as a quantum dot, and/or the like.
For example, the interlayer 130 may include a quantum dot. Here, the quantum dot is the same as described above.
In one or more embodiments, the interlayer 130 may include, i) two or more emitting units sequentially stacked between the first electrode 110 and the second electrode 150, and ii) a charge generation layer between the two or more emitting units. When the interlayer 130 includes the two or more emitting units and the charge generation layer, the light-emitting device 30 may be a tandem light-emitting device.
The hole transport region may have: i) a single-layered structure including (e.g., consisting of) a single layer including (e.g., consisting of) a single material, ii) a single-layered structure including (e.g., consisting of) a single layer including (e.g., consisting of) multiple materials that are different from each other, or iii) a multi-layered structure including multiple materials including multiple materials that are different from each other.
The hole transport region may include a hole injection layer, a hole transport layer, an emission auxiliary layer, an electron blocking layer, or any combination thereof.
For example, the hole transport region may have a multi-layered structure including a hole injection layer/hole transport layer structure, a hole injection layer/hole transport layer/emission auxiliary layer structure, a hole injection layer/emission auxiliary layer structure, a hole transport layer/emission auxiliary layer structure, or a hole injection layer/hole transport layer/electron blocking layer structure, wherein constituent layers of each structure are stacked sequentially from the first electrode 110.
The hole transport region may include a compound represented by Formula 201, a compound represented by Formula 202, or any combination thereof:
wherein, in Formulae 201 and 202,
L201 to L204 may each independently be a C3-C60 carbocyclic group unsubstituted or substituted with at least one R10a or a C1-C60 heterocyclic group unsubstituted or substituted with at least one R10a,
L205 may be *—O—*′, *—S—*′, *—N(Q201)-*′, a C1-C20 alkylene group unsubstituted or substituted with at least one R10a, a C2-C20 alkenylene group unsubstituted or substituted with at least one R10a, a C3-C60 carbocyclic group unsubstituted or substituted with at least one R10a, or a C1-C60 heterocyclic group unsubstituted or substituted with at least one R10a,
xa1 to xa4 may each independently be an integer from 0 to 5,
xa5 may be an integer from 1 to 10,
R201 to R204 and 0201 may each independently be a C3-C60 carbocyclic group unsubstituted or substituted with at least one R10a or a C1-C60 heterocyclic group unsubstituted or substituted with at least one R10a,
R201 and R202 may optionally be bonded to each other via a single bond, a C1-C5 alkylene group unsubstituted or substituted with at least one R10a, or a C2-C5 alkenylene group unsubstituted or substituted with at least one R10a, to form a C8-C60 polycyclic group (for example, a carbazole group, etc.) unsubstituted or substituted with at least one R10a (for example, Compound HT16, etc.),
R203 and R204 may optionally be bonded to each other via a single bond, a C1-C5 alkylene group unsubstituted or substituted with at least one R10a, or a C2-C5 alkenylene group unsubstituted or substituted with at least one R10a, to form a C8-C60 polycyclic group unsubstituted or substituted with at least one R10a, and
na1 may be an integer from 1 to 4.
For example, each of Formulae 201 and 202 may include at least one of groups represented by Formulae CY201 to CY217:
wherein, in Formulae CY201 to CY217, R10b and R10c may each independently be the same as described in connection with R10a, ring CY201 to ring CY204 may each independently be a C3-C20 carbocyclic group or a C1-C20 heterocyclic group, and at least one hydrogen in Formulae CY201 to CY217 may be unsubstituted or substituted with R10a.
In one or more embodiments, in Formulae CY201 to CY217, ring CY201 to ring CY204 may each independently be a benzene group, a naphthalene group, a phenanthrene group, or an anthracene group.
In one or more embodiments, each of Formulae 201 and 202 may include at least one of the groups represented by Formulae CY201 to CY203.
In one or more embodiments, Formula 201 may include at least one of the groups represented by Formulae CY201 to CY203 and at least one of the groups represented by Formulae CY204 to CY217.
In one or more embodiments, in Formula 201, xa1 may be 1, R201 may be one of the groups represented by Formulae CY201 to CY203, xa2 may be 0, and R202 may be one of the groups represented by Formulae CY204 to CY207.
In one or more embodiments, each of Formulae 201 and 202 may not include (e.g., may exclude) the groups represented by Formulae CY201 to CY203.
In one or more embodiments, each of Formulae 201 and 202 may not include (e.g., may exclude) the groups represented by Formulae CY201 to CY203, and may include at least one of the groups represented by Formulae CY204 to CY217.
In one or more embodiments, each of Formulae 201 and 202 may not include (e.g., may exclude) the groups represented by Formulae CY201 to CY217.
For example, the hole transport region may include one or more of Compounds HT1 to HT46, m-MTDATA, TDATA, 2-TNATA, NPB(NPD), p-NPB, TPD, Spiro-TPD, Spiro-NPB, methylated NPB, TAPC, HMTPD, 4,4′,4″-tris(N-carbazolyl)triphenylamine (TCTA), polyaniline/dodecylbenzenesulfonic acid (PANI/DBSA), poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) (PEDOT/PSS), polyaniline/camphor sulfonic acid (PANI/CSA), polyaniline/poly(4-styrenesulfonate) (PANI/PSS), or any combination thereof:
A thickness of the hole transport region may be in a range of about 50 Å to about 10,000 Å, for example, about 100 Å to about 4,000 Å. When the hole transport region includes a hole injection layer, a hole transport layer, or any combination thereof, a thickness of the hole injection layer may be in a range of about 100 Å to about 9,000 Å, for example, about 100 Å to about 1,000 Å, and a thickness of the hole transport layer may be in a range of about 50 Å to about 2,000 Å, for example, about 100 Å to about 1,500 Å. When the thicknesses of the hole transport region, the hole injection layer, and the hole transport layer are within their respective ranges, satisfactory or suitable hole transporting characteristics may be obtained without a substantial increase in driving voltage.
The emission auxiliary layer may increase light-emission efficiency by compensating for an optical resonance distance according to the wavelength of light emitted by the emission layer, and the electron blocking layer may block or reduce the leakage of electrons from the emission layer to the hole transport region. One or more of the materials that may be included in the hole transport region may be included in the emission auxiliary layer and the electron blocking layer.
p-Dopant
The hole transport region may further include, in addition to the materials described above, a charge-generation material for the improvement of conductive properties. The charge-generation material may be substantially uniformly or non-substantially uniformly dispersed in the hole transport region (for example, in the form of a single layer including (e.g., consisting of) a charge-generation material).
The charge-generation material may be, for example, a p-dopant.
For example, the p-dopant may have a LUMO energy level of about −3.5 eV or less.
In one or more embodiments, the p-dopant may include a quinone derivative, a cyano group-containing compound, a compound including element EL1 and element EL2, or any combination thereof.
Examples of the quinone derivative may include TCNQ, F4-TCNQ, and the like.
Examples of the cyano group-containing compound may include HAT-CN, a compound represented by Formula 221, and the like:
wherein, in Formula 221,
R221 to R223 may each independently be a C3-C60 carbocyclic group unsubstituted or substituted with at least one R10a or a C1-C60 heterocyclic group unsubstituted or substituted with at least one R10a, and
at least one of R221 to R223 may each independently be a C3-C60 carbocyclic group or a C1-C60 heterocyclic group, each substituted with: a cyano group; —F; —Cl; —Br; —I; a C1-C20 alkyl group substituted with a cyano group, —F, —Cl, —Br, —I, or any combination thereof; or any combination thereof.
In the compound including element EL1 and element EL2, element EL1 may be metal, metalloid, or any combination thereof, and element EL2 may be non-metal, metalloid, or any combination thereof.
Examples of the metal may include (e.g., be) an alkali metal (for example, lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), etc.); alkaline earth metal (for example, beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), etc.); transition metal (for example, titanium (Ti), zirconium (Zr), hafnium (Hf), vanadium (V), niobium (Nb), tantalum (Ta), chromium (Cr), molybdenum (Mo), tungsten (W), manganese (Mn), technetium (Tc), rhenium (Re), iron (Fe), ruthenium (Ru), osmium (Os), cobalt (Co), rhodium (Rh), iridium (Ir), nickel (Ni), palladium (Pd), platinum (Pt), copper (Cu), silver (Ag), gold (Au), etc.); post-transition metal (for example, zinc (Zn), indium (In), tin (Sn), etc.); lanthanide metal (for example, lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), etc.); and the like.
Examples of the metalloid may include (e.g., be) silicon (Si), antimony (Sb), tellurium (Te), and the like.
Examples of the non-metal may include (e.g., be) oxygen (O), halogen (for example, F, Cl, Br, I, etc.), and the like.
Examples of the compound including element EL1 and element EL2 may include (e.g., be) metal oxide, metal halide (for example, metal fluoride, metal chloride, metal bromide, metal iodide, etc.), metalloid halide (for example, metalloid fluoride, metalloid chloride, metalloid bromide, metalloid iodide, etc.), metal telluride, and any combination thereof.
Examples of the metal oxide may include (e.g., be) tungsten oxide (for example, WO, W2O3, WO2, WO3, W2O5, etc.), vanadium oxide (for example, VO, V2O3, VO2, V2O5, etc.), molybdenum oxide (for example, MoO, Mo2O3, MoO2, MoO3, Mo2O5, etc.), rhenium oxide (for example, ReO3, etc.), and the like.
Examples of the metal halide may include (e.g., be) alkali metal halide, alkaline earth metal halide, transition metal halide, post-transition metal halide, lanthanide metal halide, and the like.
Examples of the alkali metal halide may include (e.g., be) LiF, NaF, KF, RbF, CsF, LiCl, NaCl, KCl, RbCl, CsCl, LiBr, NaBr, KBr, RbBr, CsBr, LiI, NaI, KI, RbI, CsI, and the like.
Examples of the alkaline earth metal halide may include (e.g., be) BeF2, MgF2, CaF2, SrF2, BaF2, BeCl2, MgCl2, CaCl2), SrCl2, BaCl2, BeBr2, MgBr2, CaBr2, SrBr2, BaBr2, BeI2, MgI2, CaI2, SrI2, BaI2, and the like.
Examples of the transition metal halide may include (e.g., be) titanium halide (for example, TiF4, TiCl4, TiBr4, TiI4, etc.), zirconium halide (for example, ZrF4, ZrCl4, ZrBr4, ZrI4, etc.), hafnium halide (for example, HfF4, HfCl4, HfBr4, Hfl4, etc.), vanadium halide (for example, VF3, VCl3, VBr3, VI3, etc.), niobium halide (for example, NbF3, NbCl3, NbBr3, NbI3, etc.), tantalum halide (for example, TaF3, TaCl3, TaBr3, TaI3, etc.), chromium halide (for example, CrF3, CrCl3, CrBr3, CrI3, etc.), molybdenum halide (for example, MoF3, MoCl3, MoBr3, MoI3, etc.), tungsten halide (for example, WF3, WCl3, WBr3, WI3, etc.), manganese halide (for example, MnF2, MnCl2, MnBr2, MnI2, etc.), technetium halide (for example, TcF2, TcCl2, TcBr2, TcI2, etc.), rhenium halide (for example, ReF2, ReCl2, ReBr2, ReI2, etc.), iron halide (for example, FeF2, FeCl2, FeBr2, FeI2, etc.), ruthenium halide (for example, RuF2, RuCl2, RuBr2, RuI2, etc.), osmium halide (for example, OsF2, OsCl2, OsBr2, OsI2, etc.), cobalt halide (for example, CoF2, CoCl2, CoBr2, CoI2, etc.), rhodium halide (for example, RhF2, RhCl2, RhBr2, RhI2, etc.), iridium halide (for example, IrF2, IrCl2, IrBr2, IrI2, etc.), nickel halide (for example, NiF2, NiCl2, NiBr2, NiI2, etc.), palladium halide (for example, PdF2, PdCl2, PdBr2, PdI2, etc.), platinum halide (for example, PtF2, PtCl2, PtBr2, PtI2, etc.), copper halide (for example, CuF, CuCl, CuBr, CuI, etc.), silver halide (for example, AgF, AgCl, AgBr, AgI, etc.), gold halide (for example, AuF, AuCl, AuBr, AuI, etc.), and the like.
Examples of the post-transition metal halide may include (e.g., be) zinc halide (for example, ZnF2, ZnCl2, ZnBr2, ZnI2, etc.), indium halide (for example, InI3, etc.), tin halide (for example, SnI2, etc.), and the like.
Examples of the lanthanide metal halide may include (e.g., be) YbF, YbF2, YbF3, SmF3, YbCl, YbCl2, YbCl3 SmCl3, YbBr, YbBr2, YbBr3 SmBr3, YbI, YbI2, YbI3, SmI3, and the like.
Examples of the metalloid halide may include (e.g., be) antimony halide (for example, SbCl5, etc.) and the like.
Examples of the metal telluride may include (e.g., be) alkali metal telluride (for example, Li2Te, Na2Te, K2Te, Rb2Te, Cs2Te, etc.), alkaline earth metal telluride (for example, BeTe, MgTe, CaTe, SrTe, BaTe, etc.), transition metal telluride (for example, TiTe2, ZrTe2, HfTe2, V2Te3, Nb2Te3, Ta2Te3, Cr2Te3, Mo2Te3, W2Te3, MnTe, TcTe, ReTe, FeTe, RuTe, OsTe, CoTe, RhTe, IrTe, NiTe, PdTe, PtTe, Cu2Te, CuTe, Ag2Te, AgTe, Au2Te, etc.), post-transition metal telluride (for example, ZnTe, etc.), lanthanide metal telluride (for example, LaTe, CeTe, PrTe, NdTe, PmTe, EuTe, GdTe, TbTe, DyTe, HoTe, ErTe, TmTe, YbTe, LuTe, etc.), and the like.
When the light-emitting device 30 is a full-color light-emitting device, the emission layer may be patterned into a red emission layer, a green emission layer, and/or a blue emission layer, according to a sub-pixel. In one or more embodiments, the emission layer may have a stacked structure of two or more layers of a red emission layer, a green emission layer, and a blue emission layer, in which the two or more layers contact each other or are separated from each other to emit white light. In one or more embodiments, the emission layer may include two or more materials of a red light-emitting material, a green light-emitting material, and a blue light-emitting material, in which the two or more materials are mixed with each other in a single layer to emit white light.
The emission layer may include a host and a dopant. The dopant may include a phosphorescent dopant, a fluorescent dopant, or any combination thereof.
In the emission layer, an amount of the dopant may be in a range of about 0.01 part by weight to about 15 parts by weight based on 100 parts by weight of the host.
In one or more embodiments, the emission layer may include the quantum dot.
In one or more embodiments, the emission layer may include a delayed fluorescence material. The delayed fluorescence material may act as a host or a dopant in the emission layer.
A thickness of the emission layer may be in a range of about 100 Å to about 1,000 Å, for example, about 200 Å to about 600 Å. When the thickness of the emission layer is within any of these ranges, excellent or improved luminescence characteristics may be obtained without a substantial increase in driving voltage.
In one or more embodiments, the host may include a compound represented by Formula 301:
[Ar301]xb11-[(L301)xb1-R301]xb21, Formula 301
wherein, in Formula 301,
Ar301 and L301 may each independently be a C3-C60 carbocyclic group unsubstituted or substituted with at least one R10a or a C1-C60 heterocyclic group unsubstituted or substituted with at least one R10a,
xb11 may be 1, 2, or 3,
xb1 may be an integer from 0 to 5,
R301 may be hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, a C1-C60 alkyl group unsubstituted or substituted with at least one R10a, a C2-C60 alkenyl group unsubstituted or substituted with at least one R10a, a C2-C60 alkynyl group unsubstituted or substituted with at least one R10a, a C1-C60 alkoxy group unsubstituted or substituted with at least one R10a, a C3-C60 carbocyclic group unsubstituted or substituted with at least one R10a, a C1-C60 heterocyclic group unsubstituted or substituted with at least one R10a, —Si(Q301)(Q302)(Q303), —N(Q301)(Q302), —B(Q301)(Q302), —C(═O)(Q301), —S(═O)2(Q301), or —P(═O)(Q301)(Q302),
xb21 may be an integer from 1 to 5, and
Q301 to Q303 may each be the same as described in connection with Q1.
For example, when xb11 in Formula 301 is 2 or more, two or more of Ar301 may be bonded to each other via a single bond.
In one or more embodiments, the host may include a compound represented by Formula 301-1, a compound represented by Formula 301-2, or any combination thereof:
wherein, in Formulae 301-1 and 301-2,
ring A301 to ring A304 may each independently be a C3-C60 carbocyclic group unsubstituted or substituted with at least one R10a or a C1-C60 heterocyclic group unsubstituted or substituted with at least one R10a,
X301 may be O, S, N-[(L304)xb4-R304], C(R304)(R305), or Si(R304)(R305),
xb22 and xb23 may each independently be 0, 1, or 2,
L301, xb1, and R301 may each be respectively the same as described herein,
L302 to L304 may each independently be the same as described in connection with L301,
xb2 to xb4 may each independently be the same as described in connection with xb1, and
R302 to R305 and R311 to R314 may each independently be the same as described in connection with R301.
In one or more embodiments, the host may include an alkali earth metal complex, a post-transition metal complex, or any combination thereof. In one or more embodiments, the host may include a Be complex (for example, Compound H55), an Mg complex, a Zn complex, or any combination thereof.
In one or more embodiments, the host may include: one or more of Compounds H1 to H124; 9,10-di(2-naphthyl)anthracene (ADN); 2-methyl-9,10-bis(naphthalen-2-yl)anthracene (MADN); 9,10-di-(2-naphthyl)-2-t-butyl-anthracene (TBADN); 4,4′-bis(N-carbazolyl)-1,1′-biphenyl (CBP); 1,3-di-9-carbazolylbenzene (mCP); 1,3,5-tri(carbazol-9-yl) benzene (TCP); or any combination thereof:
The phosphorescent dopant may include at least one transition metal as a central metal.
The phosphorescent dopant may include a monodentate ligand, a bidentate ligand, a tridentate ligand, a tetradentate ligand, a pentadentate ligand, a hexadentate ligand, or any combination thereof.
The phosphorescent dopant may be electrically neutral.
For example, the phosphorescent dopant may include an organometallic compound represented by Formula 401:
M(L401)xc1(L402)xc2 Formula 401
wherein, in Formulae 401 and 402,
For example, in Formula 402, i) X401 may be nitrogen and X402 may be carbon, or ii) each of X401 and X402 may be nitrogen.
When xc1 in Formula 401 is 2 or more, in two or more of L401, two ring A401(s) may optionally be linked to each other via T402, which is a linking group, and/or two ring A402(s) may optionally be linked to each other via T403, which is a linking group. T402 and T403 may each independently be the same as described in connection with T401.
In Formula 401, L402 may be an organic ligand. For example, L402 may include a halogen group, a diketone group (for example, an acetylacetonate group), a carboxylic acid group (for example, a picolinate group), —C(═O), an isonitrile group, a —CN group, a phosphorus group (for example, a phosphine group, a phosphite group, etc.), or any combination thereof.
The phosphorescent dopant may include, for example, one or more of Compounds PD1 to PD39, or any combination thereof:
The fluorescent dopant may include an amine group-containing compound, a styryl group-containing compound, or any combination thereof.
For example, the fluorescent dopant may include a compound represented by Formula 501:
wherein, in Formula 501,
In one or more embodiments, Ar501 in Formula 501 may be a condensed cyclic group (for example, an anthracene group, a chrysene group, a pyrene group, etc.) in which three or more monocyclic groups are condensed together.
In one or more embodiments, xd4 in Formula 501 may be 2.
For example, the fluorescent dopant may include: one or more of Compounds FD1 to FD36; DPVBi; DPAVBi; or any combination thereof:
The emission layer may include a delayed fluorescence material.
In the present specification, the delayed fluorescence material may be selected from compounds capable of emitting delayed fluorescence based on a delayed fluorescence emission mechanism.
The delayed fluorescence material included in the emission layer may act as a host or a dopant depending on the type (or kind) of other materials included in the emission layer.
In one or more embodiments, a difference between a triplet energy level (eV) of the delayed fluorescence material and the singlet energy level (eV) of the delayed fluorescence material may be 0 eV or more and 0.5 eV or less. When the difference between the triplet energy level (eV) of the delayed fluorescence material and the singlet energy level (eV) of the delayed fluorescence material is satisfied within the range above, up-conversion from the triplet state to the singlet state of the delayed fluorescence materials may effectively or suitably occur, and thus, the light-emitting device 30 may have improved luminescence efficiency.
For example, the delayed fluorescence material may include: i) a material including at least one electron donor (for example, a π electron-rich C3-C60 cyclic group and/or the like, such as a carbazole group) and at least one electron acceptor (for example, a sulfoxide group, a cyano group, a π electron-deficient nitrogen-containing C1-C60 cyclic group, and/or the like), ii) a material including a C8-C60 polycyclic group including at least two cyclic groups condensed to each other while sharing boron (B), and/or the like.
Examples of the delayed fluorescence material may include at least one of Compounds DF1 to DF9:
The electron transport region may have: i) a single-layered structure including (e.g., consisting of) a single layer including (e.g., consisting of) a single material, ii) a single-layered structure including (e.g., consisting of) a single layer including (e.g., consisting of) multiple materials that are different from each other, or iii) a multi-layered structure including multiple layers including multiple materials that are different from each other.
The electron transport region may include a buffer layer, a hole blocking layer, an electron control layer, an electron transport layer, an electron injection layer, or any combination thereof.
For example, the electron transport region may have an electron transport layer/electron injection layer structure, a hole blocking layer/electron transport layer/electron injection layer structure, an electron control layer/electron transport layer/electron injection layer structure, or a buffer layer/electron transport layer/electron injection layer structure, wherein constituent layers of each structure are sequentially stacked from the emission layer (in the stated order).
In one or more embodiments, the electron transport region (for example, the buffer layer, the hole blocking layer, the electron control layer, and/or the electron transport layer in the electron transport region) may include a metal-free compound including at least one π electron-deficient nitrogen-containing C1-C60 cyclic group.
For example, the electron transport region may include a compound represented by Formula 601:
[Ar601]xe11-[(L601)xe1-R601]xe21, Formula 601
wherein, in Formula 601,
For example, when xe11 in Formula 601 is 2 or more, two or more of Ar601 may be linked to each other via a single bond.
In one or more embodiments, Ar601 in Formula 601 may be a substituted or unsubstituted anthracene group.
In one or more embodiments, the electron transport region may include a compound represented by Formula 601-1:
wherein, in Formula 601-1,
For example, xe1 and xe611 to xe613 in Formulae 601 and 601-1 may each independently be 0, 1, or 2.
In one or more embodiments, the electron transport region may include one or more of Compounds ET1 to ET45, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), 4,7-diphenyl-1,10-phenanthroline (Bphen), Alq3, BAlq, TAZ, NTAZ, or any combination thereof:
A thickness of the electron transport region may be in a range of about 100 Å to about 5,000 Å, for example, about 160 Å to about 4,000 Å. When the electron transport region includes a buffer layer, a hole blocking layer, an electron control layer, an electron transport layer, or any combination thereof, a thickness of the buffer layer, the hole blocking layer, or the electron control layer may be in a range of about 20 Å to about 1,000 Å, for example, about 30 Å to about 300 Å, and a thickness of the electron transport layer may be in a range of about 100 Å to about 1,000 Å, for example, about 150 Å to about 500 Å. When the thickness of the buffer layer, the hole blocking layer, the electron control layer, and/or the electron transport layer are within any of their respective ranges, satisfactory or suitable electron transporting characteristics may be obtained without a substantial increase in driving voltage.
The electron transport region (for example, the electron transport layer in the electron transport region) may further include, in addition to the materials described above, a metal-containing material.
The metal-containing material may include an alkali metal complex, an alkaline earth metal complex, or any combination thereof. The metal ion of an alkali metal complex may be a Li ion, a Na ion, a K ion, a Rb ion, or a Cs ion, and the metal ion of an alkaline earth metal complex may be a Be ion, a Mg ion, a Ca ion, a Sr ion, or a Ba ion. A ligand coordinated with the metal ion of the alkali metal complex or the alkaline earth-metal complex may include a hydroxyquinoline, a hydroxyisoquinoline, a hydroxybenzoquinoline, a hydroxyacridine, a hydroxyphenanthridine, a hydroxyphenyloxazole, a hydroxyphenylthiazole, a hydroxyphenyloxadiazole, a hydroxyphenylthiadiazole, a hydroxyphenylpyridine, a hydroxyphenylbenzimidazole, a hydroxyphenylbenzothiazole, a bipyridine, a phenanthroline, a cyclopentadiene, or any combination thereof.
For example, the metal-containing material may include a Li complex. The Li complex may include, for example, Compound ET-D1 (LiQ) and/or Compound ET-D2:
The electron transport region may include an electron injection layer that facilitates the injection of electrons from the second electrode 150. The electron injection layer may directly contact the second electrode 150.
The electron injection layer may have: i) a single-layered structure including (e.g., consisting of) a single layer including (e.g., consisting of) a single material, ii) a single-layered structure including (e.g., consisting of) a single layer including (e.g., consisting of) a plurality of different materials, or iii) a multi-layered structure including a plurality of layers including different materials.
The electron injection layer may include an alkali metal, alkaline earth metal, a rare earth metal, an alkali metal-containing compound, alkaline earth metal-containing compound, a rare earth metal-containing compound, an alkali metal complex, an alkaline earth metal complex, a rare earth metal complex, or any combination thereof.
The alkali metal may include Li, Na, K, Rb, Cs, or any combination thereof. The alkaline earth metal may include Mg, Ca, Sr, Ba, or any combination thereof. The rare earth metal may include Sc, Y, Ce, Tb, Yb, Gd, or any combination thereof.
The alkali metal-containing compound, the alkaline earth metal-containing compound, and the rare earth metal-containing compound may each independently be oxides, halides (for example, fluorides, chlorides, bromides, iodides, etc.), or tellurides of the alkali metal, the alkaline earth metal, and the rare earth metal, or any combination thereof.
The alkali metal-containing compound may include: an alkali metal oxide, such as Li2O, Cs2O, K2O, and/or the like; alkali metal halides, such as LiF, NaF, CsF, KF, LiI, NaI, CsI, KI, and/or the like; or any combination thereof. The alkaline earth metal-containing compound may include an alkaline earth metal compound, such as BaO, SrO, CaO, BaxSr1-xO (wherein x is a real number satisfying 0<x<1), BaxCa1-xO (wherein x is a real number satisfying 0<x<1), and/or the like. The rare earth metal-containing compound may include YbF3, ScF3, Sc2O3, Y2O3, Ce2O3, GdF3, TbF3, YbI3, ScI3, TbI3, or any combination thereof. In one or more embodiments, the rare earth metal-containing compound may include lanthanide metal telluride. Examples of the lanthanide metal telluride may include (e.g., be) LaTe, CeTe, PrTe, NdTe, PmTe, SmTe, EuTe, GdTe, TbTe, DyTe, HoTe, ErTe, TmTe, YbTe, LuTe, La2Te3, Ce2Te3, Pr2Te3, Nd2Te3, Pm2Te3, Sm2Te3, Eu2Te3, Gd2Te3, Tb2Te3, Dy2Te3, Ho2Te3, Er2Te3, Tm2Te3, Yb2Te3, Lu2Te3, and the like.
The alkali metal complex, the alkaline earth-metal complex, and the rare earth metal complex may include i) one of ions of the alkali metal, the alkaline earth metal, and the rare earth metal, respectively, and ii), as a ligand bonded to the metal ion, for example, hydroxyquinoline, hydroxyisoquinoline, hydroxybenzoquinoline, hydroxyacridine, hydroxyphenanthridine, hydroxyphenyloxazole, hydroxyphenylthiazole, hydroxyphenyloxadiazole, hydroxyphenylthiadiazole, hydroxyphenylpyridine, hydroxyphenyl benzimidazole, hydroxyphenylbenzothiazole, bipyridine, phenanthroline, cyclopentadiene, or any combination thereof.
In one or more embodiments, the electron injection layer may include (e.g., may consist of) an alkali metal, an alkaline earth metal, a rare earth metal, an alkali metal-containing compound, an alkaline earth metal-containing compound, a rare earth metal-containing compound, an alkali metal complex, an alkaline earth metal complex, a rare earth metal complex, or any combination thereof, as described above. In one or more embodiments, the electron injection layer may further include an organic material (for example, a compound represented by Formula 601).
In one or more embodiments, the electron injection layer may include (e.g., may consist of) i) an alkali metal-containing compound (for example, alkali metal halide), ii) a) an alkali metal-containing compound (for example, alkali metal halide); and b) an alkali metal, an alkaline earth metal, a rare earth metal, or any combination thereof. For example, the electron injection layer may be a KI:Yb co-deposited layer, an RbI:Yb co-deposited layer, and/or the like.
When the electron injection layer further includes an organic material, the alkali metal, the alkaline earth metal, the rare earth metal, the alkali metal-containing compound, the alkaline earth metal-containing compound, the rare earth metal-containing compound, the alkali metal complex, the alkaline earth-metal complex, the rare earth metal complex, or any combination thereof may be substantially uniformly or non-substantially uniformly dispersed in a matrix including the organic material.
A thickness of the electron injection layer may be in a range of about 1 Å to about 100 Å, and, for example, about 3 Å to about 90 Å. When the thickness of the electron injection layer is within any of the ranges above, satisfactory or suitable electron injection characteristics may be obtained without a substantial increase in driving voltage.
The second electrode 150 may be arranged on the interlayer 130 having the structure as described above. The second electrode 150 may be a cathode, which is an electron injection electrode, and as a material for forming the second electrode 150, a metal, an alloy, an electrically conductive compound, or any combination thereof, each having a low-work function, may be used.
The second electrode 150 may include lithium (Li), silver (Ag), magnesium (Mg), aluminum (Al), aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In), magnesium-silver (Mg—Ag), ytterbium (Yb), silver-ytterbium (Ag—Yb), ITO, IZO, or any combination thereof. The second electrode 150 may be a transmissive electrode, a semi-transmissive electrode, or a reflective electrode.
The second electrode 150 may have a single-layered structure or a multi-layered structure including a plurality of layers.
A first capping layer may be arranged outside the first electrode 110, and/or a second capping layer may be arranged outside the second electrode 150. In one or more embodiments, the light-emitting device 30 may have a structure in which the first capping layer, the first electrode 110, the interlayer 130, and the second electrode 150 are sequentially stacked in the stated order, a structure in which the first electrode 110, the interlayer 130, the second electrode 150, and the second capping layer are sequentially stacked in the stated order, or a structure in which the first capping layer, the first electrode 110, the interlayer 130, the second electrode 150, and the second capping layer are sequentially stacked in the stated order.
Light generated in the emission layer of the interlayer 130 of the light-emitting device 30 may be extracted toward the outside through the first electrode 110, which is a semi-transmissive electrode or a transmissive electrode, and the first capping layer. Light generated in the emission layer of the interlayer 130 of the light-emitting device 30 may be extracted toward the outside through the second electrode 150, which is a semi-transmissive electrode or a transmissive electrode, and the second capping layer.
The first capping layer and the second capping layer may increase external emission efficiency according to the principle of constructive interference. Accordingly, the light extraction efficiency of the light-emitting device 30 is increased, so that the luminescence efficiency of the light-emitting device 30 may be improved.
The first capping layer and the second capping layer may each independently include a material having a refractive index of greater than or equal to 1.6 (at 589 nm).
The first capping layer and the second capping layer may each independently be an organic capping layer including an organic material, an inorganic capping layer including an inorganic material, or an organic-inorganic composite capping layer including an organic material and an inorganic material.
At least one of the first capping layer or the second capping layer may each independently include a carbocyclic compound, a heterocyclic compound, an amine group-containing compound, a porphine derivative, a phthalocyanine derivative, a naphthalocyanine derivative, an alkali metal complex, an alkaline earth metal complex, or any combination thereof. The carbocyclic compound, the heterocyclic compound, and the amine group-containing compound may optionally be substituted with a substituent including O, N, S, Se, Si, F, Cl, Br, I, or any combination thereof. In one or more embodiments, at least one of the first capping layer or the second capping layer may each independently include an amine group-containing compound.
In one or more embodiments, at least one of the first capping layer or the second capping layer may each independently include a compound represented by Formula 201, a compound represented by Formula 202, or any combination thereof.
In one or more embodiments, at least one of the first capping layer or the second capping layer may each independently include: one or more of Compounds HT28 to HT33; one or more of Compounds CP1 to CP6; β-NPB; or any combination thereof:
The quantum dot may be included in one or more suitable films. Accordingly, one or more embodiments of the disclosure provide a film including the quantum dot. The film may be, for example, an optical member (or a light control means) (for example, a color filter, a color-conversion member, a capping layer, a light extraction efficiency enhancement layer, a selective light absorbing layer, a polarizing layer, a quantum dot-containing layer, and/or like), a light-blocking member (for example, a light reflective layer, a light absorbing layer, and/or the like), a protective member (for example, an insulating layer, a dielectric layer, and/or the like).
The light-emitting device may be included in one or more suitable electronic apparatuses. For example, the electronic apparatus including the light-emitting device may be a light-emitting apparatus, an authentication apparatus, and/or the like.
The electronic apparatus (for example, a light-emitting apparatus) may further include, in addition to the light-emitting device, i) a color filter, ii) a color conversion layer, or iii) a color filter and a color conversion layer. The color filter and/or the color conversion layer may be arranged in at least one traveling direction of light emitted from the light-emitting device. For example, the light emitted from the light-emitting device may be blue light or white light. The light-emitting device may be the same as described herein. In one or more embodiments, the color conversion layer may include a quantum dot. The quantum dot may be, for example, the same as described herein.
The electronic apparatus may include a first substrate. The first substrate may include a plurality of subpixel areas, the color filter may include a plurality of color filter areas respectively corresponding to the subpixel areas, and the color conversion layer may include a plurality of color conversion areas respectively corresponding to the subpixel areas.
A pixel-defining film may be arranged among the subpixel areas to define each of the subpixel areas.
The color filter may further include a plurality of color filter areas and light-shielding patterns arranged among the color filter areas, and the color conversion layer may further include a plurality of color conversion areas and light-shielding patterns arranged among the color conversion areas.
The plurality of color filter areas (and/or the plurality of color conversion areas) may include a first area emitting first color light, a second area emitting second color light, and/or a third area emitting third color light, wherein the first color light, the second color light, and/or the third color light may have different maximum emission wavelengths from one another. For example, the first color light may be red light, the second color light may be green light, and the third color light may be blue light. The third color light may be blue light having a maximum emission wavelength in a range of about 400 nm to about 490 nm.
For example, the plurality of color filter areas (and/or the plurality of color conversion areas) may include quantum dots. In one or more embodiments, the first area may include a red quantum dot, the second area may include a green quantum dot, and the third area may include a quantum dot. The quantum dot included in the third region may emit blue light having a maximum emission wavelength in a range of about 440 nm to about 470 nm.
The quantum dot may be the same as described herein. The first area, the second area, and/or the third area may each further include a scatter.
For example, the light-emitting device may emit first light, the first area may absorb the first light to emit first-first color light, the second area may absorb the first light to emit second-first color light, and the third area may absorb the first light to emit third-first color light. Here, the first-first color light, the second-first color light, and the third-first color light may have different maximum emission wavelengths. For example, the first light may be blue light, the first-first color light may be red light, the second-first color light may be green light, and the third-first color light may be blue light.
The electronic apparatus may further include a thin-film transistor, in addition to the light-emitting device as described above. The thin-film transistor may include a source electrode, a drain electrode, and an activation layer, wherein one of the source electrode or the drain electrode may be electrically connected to one of the first electrode or the second electrode of the light-emitting device.
The thin-film transistor may further include a gate electrode, a gate insulating film, and/or the like.
The activation layer may include crystalline silicon, amorphous silicon, an organic semiconductor, an oxide semiconductor, and/or the like.
The electronic apparatus may further include a sealing portion for sealing the light-emitting device. The sealing portion may be arranged between the color filter and/or the color conversion layer and the light-emitting device. The sealing portion allows light from the light-emitting device to be extracted to the outside, and simultaneously or concurrently prevents or reduces the penetration of ambient air and/or moisture into the light-emitting device. The sealing portion may be a sealing substrate including a transparent glass substrate and/or a plastic substrate. The sealing portion may be a thin-film encapsulation layer including at least one layer of an organic layer and/or an inorganic layer. When the sealing portion is a thin film encapsulation layer, the electronic apparatus may be flexible.
One or more suitable functional layers may be additionally arranged on the sealing portion, in addition to the color filter and/or the color conversion layer, according to the use of the electronic apparatus. Examples of the functional layers may include a touch screen layer, a polarizing layer, and/or the like. The touch screen layer may be a pressure-sensitive touch screen layer, a capacitive touch screen layer, and/or an infrared touch screen layer. The authentication apparatus may be, for example, a biometric authentication apparatus that authenticates an individual by using biometric information of a living body (for example, fingertips, pupils, etc.).
The authentication apparatus may further include, in addition to the light-emitting device as described above, a biometric information collector.
The electronic apparatus may be applied to one or more suitable displays, light sources, lighting, personal computers (for example, a mobile personal computer), mobile phones, digital cameras, electronic organizers, electronic dictionaries, electronic game machines, medical instruments (for example, electronic thermometers, sphygmomanometers, blood glucose meters, pulse measurement devices, pulse wave measurement devices, electrocardiogram displays, ultrasonic diagnostic devices, and/or endoscope displays), fish finders, various measuring instruments, meters (for example, meters for a vehicle, an aircraft, and/or a vessel), projectors, and/or the like.
One or more embodiments of the present disclosure provide an optical member including the quantum dot.
The optical member may be a color-conversion member.
The color-conversion member may include a substrate and a pattern layer formed on the substrate.
The substrate may be a substrate constituting the color-conversion member, or may be a region of an apparatus (e.g., various suitable apparatuses) (for example, a display apparatus) in which the color-conversion member is arranged. The substrate may be glass, silicon (Si), silicon oxide (SiOx), and/or a polymer substrate, and the polymer substrate may be polyethersulfone (PES) and/or polycarbonate (PC).
The pattern layer may include a quantum dot in the form of a thin film. For example, the pattern layer may be a thin-film quantum dot.
The color-conversion member including the substrate and the pattern layer may further include a partition wall or a black matrix formed between pattern layers. The color-conversion member may further include a color filter to further improve light conversion efficiency.
The color-conversion member may include a red pattern layer capable of emitting red light, a green pattern layer capable of emitting green light, a blue pattern layer capable of emitting blue light, or any combination thereof. The red pattern layer, the green pattern layer and/or the blue pattern layer may be implemented by controlling the components, compositions, and/or structures of the quantum dots.
One or more other embodiments of the disclosure provide an apparatus including the quantum dot (or the optical member including the quantum dot).
The apparatus may further include a light source, and the quantum dot (or the optical member including the quantum dot) may be arranged in a path of light emitted from the light source.
The light source may emit blue light, red light, green light, or white light. For example, the light source may emit blue light.
The light source may be an organic light-emitting device (OLED) or a light-emitting diode (LED).
The light emitted from the light source as described above may be photoconverted by the quantum dots while passing through the quantum dots. Accordingly, due to the quantum dots, light having a wavelength that is different from that of the light emitted from the light source, may be emitted.
The apparatus may be a display apparatus, a lighting apparatus, and/or the like.
The light-emitting apparatus of
The substrate 100 may be a flexible substrate, a glass substrate, and/or a metal substrate. A buffer layer 210 may be arranged on the substrate 100. The buffer layer 210 may prevent or reduce penetration of impurities through the substrate 100 and may provide a flat (or substantially flat) surface on the substrate 100.
A TFT may be arranged on the buffer layer 210. The TFT may include an activation layer 220, a gate electrode 240, a source electrode 260, and a drain electrode 270.
The activation layer 220 may include an inorganic semiconductor such as silicon and/or polysilicon, an organic semiconductor, and/or an oxide semiconductor, and may include a source region, a drain region, and a channel region.
A gate insulating film 230 for insulating the activation layer 220 from the gate electrode 240 may be arranged on the activation layer 220, and the gate electrode 240 may be arranged on the gate insulating film 230.
An interlayer insulating film 250 may be arranged on the gate electrode 240. The interlayer insulating film 250 may be arranged between the gate electrode 240 and the source electrode 260 and between the gate electrode 240 and the drain electrode 270, to insulate from one another.
The source electrode 260 and the drain electrode 270 may be arranged on the interlayer insulating film 250. The interlayer insulating film 250 and the gate insulating film 230 may be formed to expose the source region and the drain region of the activation layer 220, and the source electrode 260 and the drain electrode 270 may be arranged in contact with the exposed portions of the source region and the drain region of the activation layer 220.
The TFT may be electrically connected to a light-emitting device to drive the light-emitting device, and may be covered and protected by a passivation layer 280. The passivation layer 280 may include an inorganic insulating film, an organic insulating film, or any combination thereof. A light-emitting device may be provided on the passivation layer 280. The light-emitting device may include a first electrode 110, an interlayer 130, and a second electrode 150.
The first electrode 110 may be arranged on the passivation layer 280. The passivation layer 280 may be arranged to expose a portion of the drain electrode 270, not fully covering the drain electrode 270, and the first electrode 110 may be arranged to be connected to the exposed portion of the drain electrode 270.
A pixel defining layer 290 including an insulating material may be arranged on the first electrode 110. The pixel defining layer 290 may expose a certain region of the first electrode 110, and an interlayer 130 may be formed in the exposed region of the first electrode 110. The pixel defining layer 290 may be a polyimide and/or polyacrylic organic film. In one or more embodiments, at least some layers of the interlayer 130 may extend beyond the upper portion of the pixel defining layer 290 and may thus be arranged in the form of a common layer.
The second electrode 150 may be arranged on the interlayer 130, and a capping layer 170 may be additionally formed on the second electrode 150. The capping layer 170 may be formed to cover the second electrode 150.
The encapsulation portion 300 may be arranged on the capping layer 170. The encapsulation portion 300 may be arranged on a light-emitting device to protect the light-emitting device from moisture and/or oxygen. The encapsulation portion 300 may include: an inorganic film including silicon nitride (SiNx), silicon oxide (SiOx), indium tin oxide, indium zinc oxide, or any combination thereof; an organic film including polyethylene terephthalate, polyethylene naphthalate, polycarbonate, polyimide, polyethylene sulfonate, polyoxymethylene, polyarylate, hexamethyldisiloxane, an acrylic resin (for example, polymethyl methacrylate, polyacrylic acid, and/or the like), an epoxy-based resin (for example, aliphatic glycidyl ether (AGE), and/or the like), or any combination thereof; or any combination of the inorganic films and the organic films.
The light-emitting apparatus of
Respective layers included in the hole transport region, the emission layer, and respective layers included in the electron transport region may be formed in a certain region by using one or more suitable methods selected from vacuum deposition, spin coating, casting, Langmuir-Blodgett (LB) deposition, ink-jet printing, laser-printing, laser-induced thermal imaging, and the like.
When respective layers included in the hole transport region, the emission layer, and respective layers included in the electron transport region are formed by vacuum deposition, the deposition may be performed at a deposition temperature of about 100° C. to about 500° C., a vacuum degree of about 10−8 torr to about 10−3 torr, and a deposition speed of about 0.01 Å/sec to about 100 Å/sec, depending on a material to be included in a layer to be formed and the structure of a layer to be formed.
The term “C3-C60 carbocyclic group” as used herein refers to a cyclic group consisting of carbon atoms only as ring-forming atoms and having three to sixty carbon atoms, and the term “C1-C60 heterocyclic group” as used herein refers to a cyclic group that has one to sixty carbon atoms and further has, in addition to carbon, at least one heteroatom as a ring-forming atom. The C3-C60 carbocyclic group and the C1-C60 heterocyclic group may each independently be a monocyclic group consisting of one ring or a polycyclic group in which two or more rings are condensed with each other. For example, the number of ring-forming atoms of the C1-C60 heterocyclic group may be from 3 to 61.
The “cyclic group” as used herein may include both the C3-C60 carbocyclic group and the C1-C60 heterocyclic group.
The term “π electron-rich C3-C60 cyclic group” as used herein refers to a cyclic group that has three to sixty carbon atoms and does not include *—N═*′ as a ring-forming moiety, and the term “π electron-deficient nitrogen-containing C1-C60 cyclic group” as used herein refers to a heterocyclic group that has one to sixty carbon atoms and includes *—N═*′ as a ring-forming moiety.
For example,
The terms “the cyclic group, the C3-C60 carbocyclic group, the C1-C60 heterocyclic group, the π electron-rich C3-C60 cyclic group, and the π electron-deficient nitrogen-containing C1-C60 cyclic group” as used herein each independently refer to a group condensed to another cyclic group, a monovalent group, or a polyvalent group (for example, a divalent group, a trivalent group, a tetravalent group, etc.) according to the structure of a formula for which the corresponding term is used. For example, the “benzene group” may be a benzo group, a phenyl group, a phenylene group, and/or the like, which may be easily understood by one of ordinary skill in the art according to the structure of a formula including the “benzene group.”
Examples of the monovalent C3-C60 carbocyclic group and the monovalent C1-C60 heterocyclic group may include a C3-C10 cycloalkyl group, a C1-C10 heterocycloalkyl group, a C3-C10 cycloalkenyl group, a C1-C10 heterocycloalkenyl group, a C6-C60 aryl group, a C1-C60 heteroaryl group, a monovalent non-aromatic condensed polycyclic group, and a monovalent non-aromatic condensed heteropolycyclic group. Examples of the divalent C3-C60 carbocyclic group and the monovalent C1-C60 heterocyclic group may include a C3-C10 cycloalkylene group, a C1-C10 heterocycloalkylene group, a C3-C10 cycloalkenylene group, a C1-C10 heterocycloalkenylene group, a C6-C60 arylene group, a C1-C60 heteroarylene group, a divalent non-aromatic condensed polycyclic group, and a substituted or unsubstituted divalent non-aromatic condensed heteropolycyclic group.
The term “C1-C60 alkyl group” as used herein refers to a linear or branched aliphatic hydrocarbon monovalent group that has one to sixty carbon atoms, and specific examples thereof may include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, an isobutyl group, a tert-butyl group, an n-pentyl group, a tert-pentyl group, a neopentyl group, an isopentyl group, a sec-pentyl group, a 3-pentyl group, a sec-isopentyl group, an n-hexyl group, an isohexyl group, a sec-hexyl group, a tert-hexyl group, an n-heptyl group, an isoheptyl group, a sec-heptyl group, a tert-heptyl group, an n-octyl group, an isooctyl group, a sec-octyl group, a tert-octyl group, an n-nonyl group, an isononyl group, a sec-nonyl group, a tert-nonyl group, an n-decyl group, an isodecyl group, a sec-decyl group, and a tert-decyl group. The term “C1-C60 alkylene group” as used herein refers to a divalent group having the same structure as the C1-C60 alkyl group.
The term “C2-C60 alkenyl group” as used herein refers to a monovalent hydrocarbon group having at least one carbon-carbon double bond in the middle and/or at the terminus of the C2-C60 alkyl group, and examples thereof may include an ethenyl group, a propenyl group, a butenyl group, and the like. The term “C2-C60 alkenylene group” as used herein refers to a divalent group having the same structure as the C2-C60 alkenyl group.
The term “C2-C60 alkynyl group” as used herein refers to a monovalent hydrocarbon group having at least one carbon-carbon triple bond in the middle and/or at the terminus of the C2-C60 alkyl group, and examples thereof may include an ethynyl group, a propynyl group, and the like. The term “C2-C60 alkynylene group” as used herein refers to a divalent group having the same structure as the C2-C60 alkynyl group.
The term “C1-C60 alkoxy group” as used herein refers to a monovalent group represented by —OA101 (wherein A101 is the C1-C60 alkyl group), and examples thereof may include a methoxy group, an ethoxy group, an isopropyloxy group, and the like.
The term “C3-C10 cycloalkyl group” as used herein refers to a monovalent saturated hydrocarbon cyclic group having 3 to 10 carbon atoms, and examples thereof may include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, an adamantanyl group, a norbornanyl group (or bicyclo[2.2.1]heptyl group), a bicyclo[1.1.1]pentyl group, a bicyclo[2.1.1]hexyl group, a bicyclo[2.2.2]octyl group, and the like. The term “C3-C10 cycloalkylene group” as used herein refers to a divalent group having the same structure as the C3-C10 cycloalkyl group.
The term “C1-C10 heterocycloalkyl group” as used herein refers to a monovalent cyclic group of 1 to 10 carbon atoms, further including, in addition to carbon atoms, at least one heteroatom, as ring-forming atoms, and examples thereof may include a 1,2,3,4-oxatriazolidinyl group, a tetrahydrofuranyl group, a tetrahydrothiophenyl group, and the like. The term “C1-C10 heterocycloalkylene group” as used herein refers to a divalent group having the same structure as the C1-C10 heterocycloalkyl group.
The term “C3-C10 cycloalkenyl group” as used herein refers to a monovalent cyclic group that has three to ten carbon atoms and at least one carbon-carbon double bond in the ring thereof and no aromaticity in its molecular structure as a whole, and examples thereof may include a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, and the like. The term “C3-C10 cycloalkenylene group” as used herein refers to a divalent group having the same structure as the C3-C10 cycloalkenyl group.
The term “C1-C10 heterocycloalkenyl group” as used herein refers to a monovalent cyclic group of 1 to 10 carbon atoms, further including, in addition to carbon atoms, at least one heteroatom, as ring-forming atoms, and having at least one carbon-carbon double bond in the cyclic structure thereof. Examples of the C1-C60 heterocycloalkenyl group may include a 4,5-dihydro-1,2,3,4-oxatriazolyl group, a 2,3-dihydrofuranyl group, a 2,3-dihydrothiophenyl group, and the like. The term “C1-C10 heterocycloalkenylene group” as used herein refers to a divalent group having the same structure as the C1-C10 heterocycloalkenyl group.
The term “C6-C60 aryl group” as used herein refers to a monovalent group having a carbocyclic aromatic system of 6 to 60 carbon atoms, and the term “C6-C60 arylene group” as used herein refers to a divalent group having the same structure as the C6-C60 aryl group. Examples of the C6-C60 aryl group may include a phenyl group, a pentalenyl group, a naphthyl group, an azulenyl group, an indacenyl group, an acenaphthyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a heptalenyl group, a naphthacenyl group, a picenyl group, a hexacenyl group, a pentacenyl group, a rubicenyl group, a coronenyl group, an ovalenyl group, and the like. When the C6-C60 aryl group and the C6-C60 arylene group each independently include two or more rings, the respective rings may be condensed with each other.
The term “C1-C60 heteroaryl group” as used herein refers to a monovalent group having a heterocyclic aromatic system of 1 to 60 carbon atoms, further including, in addition to carbon atoms, at least one heteroatom, as ring-forming atoms. The term “C1-C60 heteroarylene group” as used herein refers to a divalent group having the same structure as the C1-C60 heteroaryl group. Examples of the C1-C60 heteroaryl group may include a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, a benzoquinolinyl group, an isoquinolinyl group, a benzoisoquinolinyl group, a quinoxalinyl group, a benzoquinoxalinyl group, a quinazolinyl group, a benzoquinazolinyl group, a cinnolinyl group, a phenanthrolinyl group, a phthalazinyl group, and a naphthyridinyl group. When the C1-C60 heteroaryl group and the C1-C60 heteroarylene group each independently include two or more rings, the respective rings may be condensed with each other.
The term “monovalent non-aromatic condensed polycyclic group” as used herein refers to a monovalent group (for example, having 8 to 60 carbon atoms) having two or more rings condensed to each other, only carbon atoms as ring-forming atoms, and no aromaticity in its entire molecular structure. Examples of the monovalent non-aromatic condensed polycyclic group may include an indenyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, an indenophenanthrenyl group, an indeno anthracenyl group, and the like. The term “divalent non-aromatic condensed polycyclic group” as used herein refers to a divalent group having the same structure as the monovalent non-aromatic condensed polycyclic group described above.
The term “monovalent non-aromatic condensed heteropolycyclic group” as used herein refers to a monovalent group (for example, having 1 to 60 carbon atoms) having two or more rings condensed to each other, further including, in addition to carbon atoms, at least one heteroatom, as ring-forming atoms, and having no aromaticity in its entire molecular structure. Examples of the monovalent non-aromatic condensed heteropolycyclic group may include a pyrrolyl group, a thiophenyl group, a furanyl group, an indolyl group, a benzoindolyl group, a naphthoindolyl group, an isoindolyl group, a benzoisoindolyl group, a naphthoisoindolyl group, a benzosilolyl group, a benzothiophenyl group, a benzofuranyl group, a carbazolyl group, a dibenzosilolyl group, a dibenzothiophenyl group, a dibenzofuranyl group, an azacarbazolyl group, an azafluorenyl group, an azadibenzosilolyl group, an azadibenzothiophenyl group, an azadibenzofuranyl group, a pyrazolyl group, an imidazolyl group, a triazolyl group, a tetrazolyl group, an oxazolyl group, an isoxazolyl group, a thiazolyl group, an isothiazolyl group, an oxadiazolyl group, a thiadiazolyl group, a benzopyrazolyl group, a benzimidazolyl group, a benzoxazolyl group, a benzothiazolyl group, a benzoxadiazolyl group, a benzothiadiazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, an imidazotriazinyl group, an imidazopyrazinyl group, an imidazopyridazinyl group, an indeno carbazolyl group, an indolocarbazolyl group, a benzofurocarbazolyl group, a benzothienocarbazolyl group, a benzosilolocarbazolyl group, a benzoindolocarbazolyl group, a benzocarbazolyl group, a benzonaphthofuranyl group, a benzonaphthothiophenyl group, a benzonaphthosilolyl group, a benzofurodibenzofuranyl group, a benzofurodibenzothiophenyl group, and a benzothienodibenzothiophenyl group. The term “divalent non-aromatic condensed heteropolycyclic group” as used herein refers to a divalent group having the same structure as the monovalent non-aromatic condensed heteropolycyclic group described above.
The term “C6-C60 aryloxy group” as used herein refers to a group represented by —OA102 (wherein A102 is the C6-C60 aryl group), and the term “C6-C60 arylthio group” as used herein refers to a group represented by —SA103 (wherein A103 is the C6-C60 aryl group).
The term “C7-C60 aryl alkyl group” as used herein refers to a group represented by -A104A105 (wherein A104 is a C1-C54 alkylene group, and A105 is a C6-C59 aryl group), and the term “C2-C60 heteroarylalkyl group” as used herein refers to a group represented by -A106A107 (wherein A106 is a C1-C59 alkylene group, and A107 is a C1-C59 heteroaryl group).
The term “R10a” as used herein may be:
In the present specification, Q1 to Q3, Q11 to Q13, Q21 to Q23, and Q31 to Q33 may each independently be: hydrogen; deuterium; —F; —Cl; —Br; —I; a hydroxyl group; a cyano group; a nitro group; a C1-C60 alkyl group; a C2-C60 alkenyl group; a C2-C60 alkynyl group; a C1-C60 alkoxy group; a C3-C60 carbocyclic group or a C1-C60 heterocyclic group, each unsubstituted or substituted with deuterium, —F, a cyano group, a C1-C60 alkyl group, a C1-C60 alkoxy group, a phenyl group, a biphenyl group, or any combination thereof; a C7-C60 aryl alkyl group; or a C2-C60 heteroaryl alkyl group.
The term “heteroatom” as used herein refers to any atom other than a carbon atom. Examples of the heteroatom may include O, S, N, P, Si, B, Ge, Se, or any combination thereof.
The term “third-row transition metal” as used herein includes Hf, Ta, W, Re, Os, Ir, Pt, Au, and the like.
“Ph” as used herein refers to a phenyl group, “Me” as used herein refers to a methyl group, “Et” as used herein refers to an ethyl group, “ter-Bu” or “But” as used herein refers to a tert-butyl group, and “OMe” as used herein refers to a methoxy group.
The term “biphenyl group” as used herein refers to “a phenyl group substituted with a phenyl group.” For example, the “biphenyl group” is a substituted phenyl group having a C6-C60 aryl group as a substituent.
The term “terphenyl group” as used herein refers to “a phenyl group substituted with a biphenyl group.” For example, the “terphenyl group” is a substituted phenyl group having, as a substituent, a C6-C60 aryl group substituted with a C6-C60 aryl group.
* and *′ as used herein, unless defined otherwise, each refer to a binding site to a neighboring atom in a corresponding formula or moiety.
Hereinafter, compounds according to embodiments and light-emitting devices according to embodiments will be described in more detail with reference to the following synthesis examples and examples. The wording “B was used instead of A” used in describing Synthesis Examples means that an identical molar equivalent of B was used in place of A.
In vacuum and at temperature of 120° C., ZnSeTe core, Zn acetate (3 mmol), oleic acid (1.5 mL), and oleic amine (1 mL) were maintained for 30 minutes. Under a nitrogen stream, HF (0.2 mL) was placed and maintained for 10 minutes in vacuum at 120° C.
Under a nitrogen stream, the temperature was raised to 340° C., and into a reaction vessel containing the core, a mixed solution of 4 mL of 0.5 M Zn stock solution and 0.6 mL of 2 M TOP-Se was slowly added dropwise to form a first mixture, and a ZnSe shell was deposited on a surface of the core to form a first intermediate.
Afterwards, a mixed solution of 3 mL of 0.5 M Zn stock solution and 1.2 mL of 2 M TOP-S was slowly added dropwise thereto at 340° C. to form a third mixture, and ZnS from the third mixture was deposited on a surface of the ZnSe shell to form a second intermediate.
The reaction temperature was lowered to 150° C., and then, 0.2 mL of HF solution (TOA:HF=9:1) was added dropwise thereto to form a fifth mixture. The fifth mixture was maintained for 10 minutes in vacuum, and maintained another 30 minutes after raising the temperature to 270° C. under a nitrogen stream to form a ligand layer. The reaction was terminated by lowering the reaction temperature to room temperature, thereby synthesizing 0.3 g of BOQ 1.
BOQ 2 was synthesized in substantially the same manner as in Synthesis Example 1, except that, in forming the ligand layer, 0.5 mL of HF solution was added dropwise instead of 0.2 mL of the HF solution.
BOQ 3 was synthesized in substantially the same manner as in Synthesis Example 1, except that, in forming the ligand layer, 1.0 mL of HF solution was added dropwise instead of 0.2 mL of the HF solution.
BOQ 4 was synthesized in the same manner as in Synthesis Example 1, except that, in forming the ligand layer, 2.0 mL of HF solution was added dropwise instead of 0.2 mL of the HF solution.
Regarding the quantum dots synthesized according to Synthesis Examples, photoelectron spectroscopy (XPS) was performed thereon. For the XPS, was performed by using a Quantum 2000 (Physical Electronics, Inc.) (acceleration voltage: 0.5 keV to 15 keV, 300 W, energy dissociation: 1.0 eV, sputtering rate: 0.1 nm/min).
As an anode, an ITO substrate was cut to a size of 50 mm×50 mm×0.5 mm, sonicated with acetone, isopropyl alcohol, and pure water each for 15 minutes, and then cleaned by exposure to ultraviolet rays and ozone for 30 minutes. Then, the ITO substrate was provided to a vacuum deposition apparatus.
Poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) (PEDOT/PSS) was deposited on the ITO substrate to form a hole injection layer having a thickness of 600 Å, and poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(4,4′-(N-(4-sec-butylphenyl)diphenylamine)] (TFB) was vacuum-deposited on the hole injection layer to form a hole transport layer having a thickness of 400 Å.
BOQ 1 was deposited on the hole transport layer at a concentration of 20 mg/ml to form an emission layer having a thickness of 280 Å, and Compound ZnMgO was deposited on the emission layer to form an electron transport layer having a thickness of 280 Å. Al was deposited on the electron transport layer to form a cathode having a thickness of a 1,000 Å, thereby completing the manufacture of a light-emitting device.
Light-emitting devices were manufactured in substantially the same manner as in Example 1, except that, in forming the emission layer, quantum dots in Table 1 were respectively used instead of BOQ 1.
To evaluate characteristics of the light-emitting devices manufactured according to Examples 1 to 3 and Comparative Example 1, the luminescence efficiency at the current density of 10 mA/cm2 thereof was measured. The quantum efficiency of the light-emitting device was measured by using a quantum efficient measurement device C9920-2-12 manufactured by Hamamatsu Photonics Inc. Results of the characteristics evaluation of the light-emitting devices are shown in Table 1.
Referring to Table 1, it was confirmed that the light-emitting devices of each Example had excellent or improved luminescence efficiency and a long lifespan compared to the light-emitting device of Comparative Example 1.
According to the one or more embodiments, an energy level in a quantum dot prepared by a method of preparing a quantum dot disclosed herein may be precisely or suitably adjusted, and accordingly, a device, an optical member, and an apparatus that include the quantum dot may have improved efficiency.
It should be understood that embodiments described herein should be considered in a descriptive sense only and not for purposes of limitation. Descriptions of features or aspects within each embodiment should typically be considered as available for other similar features or aspects in other embodiments. While one or more embodiments have been described with reference to the figures, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope as defined by the following claims and their equivalents.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2022-0041192 | Apr 2022 | KR | national |
