Patent Application
20230422537
This application claims priority to and the benefit of Korean Patent Application No. 10-2022-0077806, filed on Jun. 24, 2022, in the Korean Intellectual Property Office, the entire content of which is incorporated by reference herein.
One or more embodiments relate to a light-emitting device and an electronic apparatus including the same.
Light-emitting devices are self-emissive devices that, as compared with other devices of the related art, have wide viewing angles, high contrast ratios, short response times, and excellent characteristics in terms of luminance, driving voltage, and response speed.
A light-emitting device may have a structure in which a first electrode (or a second electrode) is on a substrate, and a hole transport region, an emission layer, an electron transport region, and the second electrode (or the first electrode) are sequentially on the first electrode (or the second electrode). Holes provided from the first electrode (or the second electrode) may move toward the emission layer through the hole transport region, and electrons provided from the second electrode (or the first electrode) may move toward the emission layer through the electron transport region. Carriers, such as holes and electrons, recombine in the emission layer to produce light.
One or more embodiments include a device having improved efficiency and lifespan, as compared to other devices in the related art.
Additional aspects of embodiments 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, a light-emitting device includes:
According to one or more embodiments,
The above and other aspects and features 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 embodiments 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 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.
In other quantum dot light-emitting devices, an oxide nanoparticle electron transport layer has an important role in device quality based on its high electron mobility characteristics. However, due to the small particle size (e.g., small particle size of the quantum dots), a plurality of dangling bonds are present on the surface (e.g., on a surface of the quantum dots). This causes a defect site, and thus, causes exciton quenching and a hole current leakage path, thereby decreasing efficiency and causing difficulty in controlling driving stability. To control a surface property of such an oxide nanoparticle, a crystallinity of the oxide nanoparticle may be improved through a high- temperature heat treatment process, and a light-emitting device structure based on an inverted structure that does not (or substantially does not) impair physical properties of an emission layer, a hole transport layer, and a hole injection layer may be used.
In addition, to minimize or reduce a charge injection barrier of a common layer adjacent to the emission layer and to effectively control charges injected in the quantum dot light-emitting device, an emission layer including a compound forming a coordinate bond (which may also be referred to as a coordinate covalent bond or a dative bond) with the quantum dot may be formed to improve characteristics of the quantum dot light-emitting device.
According to one or more embodiments, a light-emitting device may include:
In an embodiment, the first electrode may include indium tin oxide (ITO), indium zinc oxide (IZO), tin oxide (SnO2), zinc oxide (ZnO), or any combination thereof.
In an embodiment, the first electrode 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 may have a single-layered structure consisting of a single layer or a multi-layered structure including a plurality of layers.
For example, because the first electrode is a reflective electrode, when the first electrode includes ITO, IZO, SnO2, ZnO, or any combination thereof, Mg, Ag, Al, Al—Li, Ca, Mg—In, Mg—Ag, or any combination thereof may concurrently (e.g., simultaneously) be included. For example, the first electrode may have a two-layered structure of Ag/ITO or a three-layered structure of ITO/Ag/ITO.
In an embodiment, the first emission layer and the second emission layer may be in direct contact with each other. For example, the first emission layer and the second emission layer may physically be in direct contact with each other.
In an embodiment, the interlayer may further include an electron transport layer, and the second emission layer and the electron transport layer may be in direct contact with each other. In an embodiment, the second emission layer and the electron transport layer may physically be in direct contact with each other.
In an embodiment, the interlayer may further include a hole transport layer, and the first emission layer and the hole transport layer may be in direct contact with each other. In an embodiment, the first emission layer and the hole transport layer may physically be in direct contact with each other.
In an embodiment, the interlayer may further include an electron transport layer and a hole transport layer, the first emission layer and the hole transport layer may physically be in direct contact (e.g., physical contact) with each other, and the second emission layer and the electron transport layer may physically be in contact with each other.
In an embodiment, the p-type compound in the first emission layer may be a compound having a highest occupied molecular orbital (HOMO) energy level of about −5.3 eV or less.
In an embodiment, a difference between the HOMO energy level of the p-type compound and a valence band of the first quantum dot in the first emission layer may be about 1.0 eV or less.
In an embodiment, the n-type compound in the second emission layer may be a compound having a lowest unoccupied molecular orbital (LUMO) energy level of about −4.0 eV or more.
In an embodiment, a difference between the LUMO energy level of the n-type compound and a conduction band of the second quantum dot in the second emission layer may be about 0.5 eV or less.
When orbital energy level values of the p-type compound and the n-type compound are within the above range, charge injection into the emission layer may be facilitated.
In an embodiment, the HOMO energy level of the p-type compound in the first emission layer may be between the valence band of the first quantum dot and the HOMO energy level of the hole transport layer. In addition, in the first emission layer, the HOMO energy level of the p-type compound may be greater than the HOMO energy level of the hole transport layer. In this case, hole injection into a quantum dot emission layer may be facilitated.
In an embodiment, the LUMO energy level of the n-type compound in the second emission layer may be between the conduction band of the second quantum dot and the LUMO energy level of the electron transport layer. In addition, in the second emission layer, the LUMO energy level of the n-type compound may be less than the LUMO energy level of the electron transport layer. In this case, electron injection into a quantum dot emission layer may be facilitated.
In an embodiment, the p-type compound may include one of the following moieties:
In an embodiment, the p-type compound may include a low molecular weight compound having a molecular weight of 1,000 or less, an oligomer compound having a molecular weight of about 1,000 to about 10,000, or a polymer compound having a molecular weight of 10,000 or more, each including one of Moieties 1 to 11, or any combination thereof. In an embodiment, the p-type compound may be one of Moieties 1 to 11.
In an embodiment, the p-type may be Compound 401:
wherein, in Compound 401, n2 is an integer from 2 to 300.
In an embodiment, the n-type compound may include one of the following moieties:
In an embodiment, the n-type compound may include a low molecular weight compound having a molecular weight of 1,000 or less, an oligomer compound having a molecular weight of about 1,000 to about 10,000, or a polymer compound having a molecular weight of 10,000 or more, each including one of Moieties 21 to 26, or any combination thereof. In an embodiment, the n-type compound may include one of Moieties 21 to 26.
According to an embodiment, the first and second quantum dots may each include: a core including a semiconductor compound; and a shell including a metal, a metalloid and/or non-metal oxide, a semiconductor compound, or a combination thereof.
Additional details of the quantum dots will be further described herein below.
In an embodiment, in the first emission layer, the first quantum dot includes a metal, and a bond between the p-type compound and the metal may be a coordinate bond (which may also be referred to as a coordinate covalent bond or dative bond).
In an embodiment, in the second emission layer, the second quantum dot includes a metal, and a bond between the n-type compound and the metal may be a coordinate bond (which may also be referred to as a coordinate covalent bond or dative bond).
Because a bond between the first quantum dot and the p-type compound in the first emission layer is a coordinate bond (which may also be referred to as a coordinate covalent bond or dative bond) and a bond between the second quantum dot and the n-type compound in the second emission layer is a coordinate bond (which may also be referred to as a coordinate covalent bond or dative bond), the p-type compound and the n-type compound may act as charge injection auxiliaries, thereby imparting a charge transport ability to the inside of the emission layer (or thereby increasing a charge transport ability of the inside of the emission layer). In addition, a light emitting position may be in the emission layer as a p-n bonding position to inhibit or reduce deterioration in an emission layer-adjacent interface.
In an embodiment, a ratio of the first quantum dot to the p-type compound may be about 1:0.1 to about 1:10.
In an embodiment, a ratio of the second quantum dot to the n-type compound may be about 1:0.1 to about 1:10.
When the ratio of the first quantum dot to the p-type compound in the first emission layer and the ratio of the second quantum dot to the n-type compound in the second emission layer are as described above, the efficiency and lifespan of the device is excellent.
Not all of the p-type compounds may form a coordinate bond with the first quantum dot. In this case, p-type compounds that do not form coordinate bonds may act as a hole transport material. Similarly, not all of the n-type compounds may form a coordinate bond with the second quantum dot. In this case, n-type compounds that do not form coordinate bonds may act as an electron transport material.
Another aspect of embodiments of the present disclosure provides an electronic apparatus including the light-emitting device.
In an embodiment, the electronic apparatus may further include a thin-film transistor,
In an embodiment, the TFT may be an oxide TFT. The oxide TFT may include, for example, an N-channel metal oxide semiconductor (NMOS). NMOS has lower hysteresis than that of a P-channel metal oxide semiconductor (PMOS).
In an embodiment, in the oxide-based TFT, a major carrier is an electron, and electron mobility is relatively high. In addition, the oxide-based TFT is good for a low-temperature process and a large area and is similar to a a-Si TFT. In addition, due to a small leakage current, the capacitance may be maintained, and thus, the device driving may be stable even at a low current and high-speed driving may be possible.
In an embodiment, the electronic apparatus may further include a color filter, a color conversion layer, a touch screen layer, a polarizing layer, or any combination thereof.
In an embodiment, a capping layer may be outside the first electrode and/or the second electrode.
The term “interlayer” as used herein refers to a single layer and/or all of a plurality of layers between the first electrode and the second electrode of the light-emitting device.
Hereinafter, the structure of the light-emitting device 10 according to an embodiment and a method of manufacturing the light-emitting device 10 will be described with reference to
First Electrode 110
In
The first electrode 110 may be a cathode, which is an electron injection electrode, and as a material for forming the first electrode 110, a metal, an alloy, an electrically conductive compound, or any combination thereof, each having a low work function, may be used.
The first electrode 110 may include lithium (Li), Ag, Mg, Al, Al—Li, Ca, Mg—In, Mg—Ag, ytterbium (Yb), silver-ytterbium (Ag—Yb), ITO, IZO, or any combination thereof. The first electrode 110 may be a transmissive electrode, a semi-transmissive electrode, or a reflective electrode.
The first electrode 110 may have a single-layered structure or a multi-layered structure including two or more layers.
The first electrode 110 may be the same as described in connection with the first electrode described above.
Interlayer 130
The interlayer 130 may be on the first electrode 110. The interlayer 130 may include an emission layer.
The interlayer 130 may further include a hole transport region between the second electrode 150 and the emission layer and an electron transport region between the emission layer and the first electrode 110.
The interlayer 130 may further include, in addition to various suitable organic materials, a metal-containing compound such as an organometallic compound, an inorganic material such as quantum dots, and/or the like.
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 emitting units and a charge generation layer as described above, the light-emitting device 10 may be a tandem light-emitting device.
Hole Transport Region in Interlayer 130
The hole transport region may have: i) a single-layered structure consisting of a single layer consisting of a single material, ii) a single-layered structure consisting of a single layer consisting of a plurality of different materials, or iii) a multi-layered structure including a plurality of layers including different materials.
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.
In an embodiment, 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, in each structure, layers are sequentially stacked from the second electrode 150.
The hole transport region may include a compound represented by Formula 201, a compound represented by Formula 202, or any combination thereof:
For example, each of Formulae 201 and 202 may include at least one of
groups represented by Formulae CY201 to CY217:
R10b and R10c in Formulae CY201 to CY217 are the same as in the description of 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, ring CY201 to ring CY204 in Formulae CY201 to CY217 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 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 a group represented by one of Formulae CY201 to CY203, xa2 may be 0, and R202 may be a group represented by one of Formulae CY204 to CY207.
In one or more embodiments, each of Formulae 201 and 202 may not include a group represented by one of Formulae CY201 to CY203.
In one or more embodiments, each of Formulae 201 and 202 may not include a group represented by one of 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 a group represented by one of Formulae CY201 to CY217.
In an embodiment, the hole transport region may include one of Compounds HT1 to HT46, m-MTDATA, TDATA, 2-TNATA, NPB(NPD), β-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 ↑. When the thicknesses of the hole transport region, the hole injection layer, and the hole transport layer are within these ranges, suitable or satisfactory 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 from 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. 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 these materials, a charge-generation material for the improvement of conductive properties (e.g., electrically conductive properties). The charge-generation material may be uniformly or non-uniformly dispersed in the hole transport region (for example, in the form of a single layer consisting of a charge-generation material).
The charge-generation material may be, for example, a p-dopant.
For example, the lowest unoccupied molecular orbital (LUMO) energy level of the p-dopant may be −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 include TCNQ, F4-TCNQ, etc.
Examples of the cyano group-containing compound include HAT-CN, and a compound represented by Formula 221:
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
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 include 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.); and 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.).
Examples of the metalloid include silicon (Si), antimony (Sb), and tellurium (Te).
Examples of the non-metal include oxygen (O) and halogen (for example, F, Cl, Br, I, etc.).
Examples of the compound including element EL1 and element EL2 include metal oxide, metal halide (for example, metal fluoride, metal chloride, metal bromide, and/or metal iodide), metalloid halide (for example, metalloid fluoride, metalloid chloride, metalloid bromide, and/or metalloid iodide), metal telluride, or any combination thereof.
Examples of the metal oxide include tungsten oxide (for example, WO, W2O3, WO2, WO3, W2O5, etc.), vanadium oxide (for example, VO, V2O3, VO2, V2O5, etc.), molybdenum oxide (MoO, Mo2O3, MoO2, MoO3, Mo2O5, etc.), and rhenium oxide (for example, ReO3, etc.).
Examples of the metal halide include alkali metal halide, alkaline earth metal halide, transition metal halide, post-transition metal halide, and lanthanide metal halide.
Examples of the alkali metal halogen include LiF, NaF, KF, RbF, CsF, LiCl, NaCl, KCl, RbCl, CsCl, LiBr, NaBr, KBr, RbBr, CsBr, LiI, NaI, KI, RbI, and CsI.
Examples of the alkaline earth metal halide include BeF2, MgF2, CaF2, SrF2, BaF2, BeCl2, MgCl2, CaCl2, SrCl2, BaCl2, BeBr2, MgBr2, CaBr2, SrBr2, BaBr2, BeI2, MgI2, CaI2, SrI2, and BaI2.
Examples of the transition metal halide include 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, HfI4, 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.), and gold halide (for example, AuF, AuCl, AuBr, AuI, etc.).
Examples of the post-transition metal halide include zinc halide (for example, ZnF2, ZnCl2, ZnBr2, ZnI2, etc.), indium halide (for example, InI3, etc.), and tin halide (for example, SnI2, etc.).
Examples of the lanthanide metal halide include YbF, YbF2, YbF3, SmF3, YbCl, YbCl2, YbCl3 SmCl3, YbBr, YbBr2, YbBr3 SmBr3, YbI, YbI2, YbI3, and SmI3.
An example of the metalloid halide includes antimony halide (for example, SbCl5, etc.).
Examples of the metal telluride include 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.), and lanthanide metal telluride (for example, LaTe, CeTe, PrTe, NdTe, PmTe, EuTe, GdTe, TbTe, DyTe, HoTe, ErTe, TmTe, YbTe, LuTe, etc.).
Emission Layer in Interlayer 130
When the light-emitting device 10 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 (e.g., physically 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 together with each other in a single layer to emit white light.
The emission layer 130 may include a quantum dot.
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 these ranges, excellent light-emission characteristics may be obtained without a substantial increase in driving voltage.
Quantum Dot
The term “quantum dots” (for example, the first quantum dot and the second quantum dot) refers to crystals of a semiconductor compound, and the quantum dots may include any suitable material that may emit light of various suitable emission wavelengths according to the size of the crystal.
A diameter of the quantum dots may be, for example, in a range of about 1 nm to about 10 nm.
The quantum dots may be synthesized by a wet chemical process, a metal organic chemical vapor deposition process, a molecular beam epitaxy process, and/or any suitable process similar thereto.
The wet chemical process is a method including mixing a precursor material together with an organic solvent and then growing a quantum dot particle crystal. 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 lower, and is easier than vapor deposition methods, such as metal organic chemical vapor deposition (MOCVD) or molecular beam epitaxy (MBE).
The first and second quantum dots may each independently include: a Group II-VI semiconductor compound; a Group III-V semiconductor compound; a Group III-VI semiconductor compound; a Group I-III-VI semiconductor compound; a Group IV-VI semiconductor compound; a Group IV element or compound; or any combination thereof.
Examples of the Group II-VI semiconductor compound include: a binary compound such as ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, MgSe, and/or MgS; a ternary compound such as ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, HgZnS, HgZnSe, HgZnTe, MgZnSe, and/or MgZnS; a quaternary compound such as HgZnSeS, HgZnSeTe, and/or HgZnSTe; or any combination thereof.
Examples of the Group III-V semiconductor compound include: a binary compound such as GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, and/or InSb; a ternary compound such as GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InGaP, InNP, InAlP, InNAs, InNSb, InPAs, and/or InPSb; a quaternary compound such as GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, and/or InAlPSb; or any combination thereof. In some embodiments, the Group III-V semiconductor compound may further include a Group II element. Examples of the Group III-V semiconductor compound further including a Group II element include InZnP, InGaZnP, InAlZnP, etc.
Examples of the Group III-VI semiconductor compound include: a binary compound, such as GaS, GaSe, Ga2Se3, GaTe, InS, InSe, In2S3, In2Se3, and/or InTe; a ternary compound, such as InGaS3, and/or InGaSe3; and any combination thereof.
Examples of the Group I-III-VI semiconductor compound include: a ternary compound, such as AgInS, AgInS2, CuInS, CuInS2, CuGaO2, AgGaO2, and/or AgAlO2; or any combination thereof.
Examples of the Group IV-VI semiconductor compound include: a binary compound, such as SnS, SnSe, SnTe, PbS, PbSe, and/or PbTe; a ternary compound, such as SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, and/or SnPbTe; a quaternary compound, such as SnPbSSe, SnPbSeTe, and/or SnPbSTe; or any combination thereof.
Examples of the Group IV element or compound include: a single element compound, such as Si or Ge; a binary compound, such as SiC and/or SiGe; or any combination thereof.
Each element included in a multi-element compound such as the binary compound, the ternary compound, and the quaternary compound may be present at a uniform concentration or non-uniform concentration in a particle.
In some embodiments, the first and second quantum dots may each independently have: a single structure in which the concentration of each element included in each of the first and second quantum dots is uniform (e.g., substantially uniform); or a core-shell double structure. For example, the material included in the core and the material included in the shell may be different from each other.
The shell of the quantum dot may act as a protective layer that prevents or reduces chemical degeneration of the core to maintain semiconductor characteristics, and/or as a charging layer that imparts electrophoretic characteristics to the quantum dot. The shell may be a single layer or a multi-layer. The interface between the core and the shell may have a concentration gradient in which the concentration of an element existing in the shell decreases along a direction toward the center of the core.
Examples of the shell of the quantum dot may include an oxide of metal, metalloid, and/or non-metal, a semiconductor compound, and any combination thereof. Examples of the oxide of metal, metalloid, and/or non-metal include a binary compound, such as SiO2, Al2O3, TiO2, ZnO, MnO, Mn2O3, Mn3O4, CuO, FeO, Fe2O3, Fe3O4, CoO, Co3O4, and/or NiO; a ternary compound, such as MgAl2O4, CoFe2O4, NiFe2O4, and/or CoMn2O4; and any combination thereof. Examples of the semiconductor compound include, as described herein, a Group II-VI semiconductor compound; a Group III-V semiconductor compound; a Group III-VI semiconductor compound; a Group I-III-VI semiconductor compound; a Group IV-VI semiconductor compound; and any combination thereof. For example, the semiconductor compound may include CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnSeS, ZnTeS, GaAs, GaP, GaSb, HgS, HgSe, HgTe, InAs, InP, InGaP, InSb, AlAs, AlP, AlSb, or any combination thereof.
The first and second quantum dots may include non-cadmium-based quantum dots.
A full width at half maximum (FWHM) of the emission wavelength spectrum of the quantum dot may be about 45 nm or less, for example, about 40 nm or less, for example, about 30 nm or less, and within these ranges, color purity and/or color reproducibility may be increased. In addition, because the light emitted through the quantum dot is emitted in all (e.g., substantially all) directions, the wide viewing angle may be improved.
In addition, the quantum dot may be in the form of a spherical particle, a pyramidal particle, a multi-arm particle, a cubic nanoparticle, a nanotube particle, a nanowire particle, a nanofiber particle, and/or a nanoplate particle.
Because the energy band gap may be adjusted by controlling the size of the quantum dot, light having various suitable wavelength bands may be obtained from the quantum dot emission layer. Accordingly, by using quantum dots of different sizes, a light-emitting device that emits light of various suitable wavelengths may be implemented. In one or more embodiments, the size of the quantum dot may be selected to emit red, green and/or blue light. In addition, the size of the quantum dot may be configured to emit white light by combination of light of various suitable colors.
Electron Transport Region in Interlayer 130
The electron transport region may have: i) a single-layered structure consisting of a single layer consisting of a single material, ii) a single-layered structure consisting of a single layer consisting of a plurality of different materials, or iii) a multi-layered structure including a plurality of layers including different materials.
The electron transport region may include an electron transport layer, a hole blocking layer, an electron injection layer, or any combination thereof.
For example, the electron transport region may have an electron injection layer/electron transport layer structure, wherein layers are stacked sequentially from the first electrode.
In an embodiment, the electron transport region (for example, the hole blocking layer, and/or the electron transport layer in the electron transport region) may include a metal-free compound including at least one 7 electron-deficient nitrogen-containing C1-C60 cyclic group.
For example, the electron transport region may include a compound represented by Formula 601 below:
[Ar601]xe11−[(L601)xe1−R601]xe21 Formula 601
For example, when xe11 in Formula 601 is 2 or more, two or more of Ar601(s) may be linked to each other via a single bond.
In other embodiments, Ar601 in Formula 601 may be a substituted or unsubstituted anthracene group.
In other embodiments, the electron transport region may include a compound represented by Formula 601-1:
For example, xe1 and xe611 to xe613 in Formulae 601 and 601-1 may each independently be 0, 1, or 2.
The electron transport region may include one 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 from 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 hole blocking layer, an electron transport layer, or any combination thereof, a thickness of the hole blocking layer may be in a range of about 20 Å to about 1,000 Å, for example, about 30 Å to about 300 Å. When the thickness of the hole blocking layer is within the range, suitable or satisfactory 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) or 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 (e.g., physically contact) the second electrode 150.
The electron injection layer may have: i) a single-layered structure consisting of a single layer consisting of a single material, ii) a single-layered structure consisting of a single layer 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 be oxides, halides (for example, fluorides, chlorides, bromides, and/or iodides), and/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: alkali metal oxides, such as Li2O, Cs2O, and/or K2O; alkali metal halides, such as LiF, NaF, CsF, KF, LiI, NaI, CsI, and/or KI; 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 xis a real number satisfying the condition of 0<x<1), BaxCa1-xO (wherein x is a real number satisfying the condition of 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 include 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, and Lu2Te3.
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 and ii), as a ligand bonded to the metal ion, for example, a hydroxyquinoline, a hydroxyisoquinoline, a hydroxybenzoquinoline, a hydroxyacridine, a hydroxyphenanthridine, a hydroxyphenyloxazole, a hydroxyphenylthiazole, a hydroxyphenyloxadiazole, a hydroxyphenylthiadiazole, a hydroxyphenylpyridine, a hydroxyphenyl benzimidazole, a hydroxyphenylbenzothiazole, a bipyridine, a phenanthroline, a cyclopentadiene, or any combination thereof.
The electron injection layer may include (or 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 (or consist of): i) an alkali metal-containing compound (for example, an alkali metal halide); or ii) a) an alkali metal-containing compound (for example, an 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, a LiF:Yb co-deposited layer, and/or the like.
When the electron injection layer further includes an organic material, 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 may be uniformly or non-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 the ranges described above, suitable or satisfactory electron injection characteristics may be obtained without a substantial increase in driving voltage.
Second Electrode 150
The second electrode 150 may be on the interlayer 130 having a structure as described above. The second electrode 150 may be an anode, and may be a semi-transmissive electrode or a transmissive electrode.
When the second electrode 150 is a semi-transmissive electrode or a transmissive electrode, Mg, Ag, Al, Al—Li, Ca, Mg—In, Mg—Ag, or any combination thereof may be used as a material for forming the second electrode 150.
The second electrode 150 may have a single-layered structure consisting of a single layer, or a multi-layered structure including a plurality of layers.
Capping Layer
A first capping layer may be outside the first electrode 110, and/or a second capping layer may be outside the second electrode 150. In some embodiments, the light-emitting device 10 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.
In an embodiment, light generated by the emission layer in the interlayer 130 of the light-emitting device 10 may be extracted to 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 10 is increased, so that the luminescence efficiency of the light-emitting device 10 may be improved.
The first capping layer and the second capping layer may each include a material having a refractive index of 1.6 or more (at a wavelength of 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 and the second capping layer may each independently include carbocyclic compounds, heterocyclic compounds, amine group-containing compounds, porphine derivatives, phthalocyanine derivatives, naphthalocyanine derivatives, alkali metal complexes, alkaline earth metal complexes, or any combination thereof. Optionally, the carbocyclic compound, the heterocyclic compound, and the amine group-containing compound may 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 and the second capping layer may each independently include an amine group-containing compound.
For example, at least one of the first capping layer and 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 and the second capping layer may each independently include one of Compounds HT28 to HT33, one of Compounds CP1 to CP6, β-NPB, or any combination thereof:
Electronic Apparatus
The light-emitting device may be included in various 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 in at least one direction in which light emitted from the light-emitting device travels. For example, the light emitted from the light-emitting device may be blue light or white light. For additional details of the light-emitting device, related description provided above may be referred to. In one or more embodiments, the color conversion layer may include a quantum dot. The quantum dot may be, for example, a quantum dot 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 located 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 located among the color filter areas, and the color conversion layer may further include a plurality of color conversion areas and light-shielding patterns located among the color conversion areas.
The plurality of color filter areas (or the plurality of color conversion areas) may include a first area that emits a first color light, a second area that emits a second color light, and/or a third area that emits a 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. For example, the plurality of color filter areas (or the plurality of color conversion areas) may include quantum dots. In some embodiments, the first area may include a red quantum dot, the second area may include a green quantum dot, and the third area may not include a quantum dot. For additional details of the quantum dot, related descriptions provided herein may be referred to. The first area, the second area, and/or the third area may each include a scatterer (e.g., a light scatterer). For example, the light-emitting device may emit a first light, the first area may
absorb the first light to emit a first-first color light, the second area may absorb the first light to emit a second-first color light, and the third area may absorb the first light to emit a third-first color light. In this regard, the first-first color light, the second-first color light, and the third-first color light may have different maximum emission wavelengths. In some embodiments, 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 any one of the source electrode and the drain electrode may be electrically connected to any one of the first electrode and 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 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 concurrently (e.g., simultaneously) prevents or reduces ambient air and/or moisture from penetrating 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.
Various suitable functional layers may be additionally 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 various 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 suitable measuring instruments, meters (for example, meters for a vehicle, an aircraft, and/or a vessel), projectors, and/or the like.
The electronic apparatus of
The substrate 100 may be a flexible substrate, a glass substrate, and/or a metal substrate. A buffer layer 210 may be on the substrate 100. The buffer layer 210 may prevent or reduce penetration of impurities through the substrate 100 and may provide a flat surface on the substrate 100.
A TFT may be 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 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 on the activation layer 220, and the gate electrode 240 may be on the gate insulating film 230.
An interlayer insulating film 250 may be on the gate electrode 240. The interlayer insulating film 250 may be 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 on the interlayer insulating film 250. The interlayer insulating film 250 and the gate insulating film 230 may 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 in contact (e.g., physical contact) with the exposed portions of the source region and the drain region of the activation layer 220.
The TFT is electrically connected to a light-emitting device to drive the light-emitting device, and is 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 is 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 on the passivation layer 280. The passivation layer 280 may expose a portion of the drain electrode 270, not fully covering the drain electrode 270, and the first electrode 110 may be connected to the exposed portion of the drain electrode 270.
A pixel defining layer 290 including an insulating material may be 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 in the exposed region of the first electrode 110. The pixel defining layer 290 may be a polyimide and/or polyacrylic organic film. In some embodiments, at least some layers (for example, the electron transport layer) in the interlayer 130 may extend beyond the upper portion of the pixel-defining film 290 to be in the form of a common layer.
The second electrode 150 may be on the interlayer 130, and a capping layer 170 may be additionally on the second electrode 150. The capping layer 170 may cover the second electrode 150.
The encapsulation portion 300 may be on the capping layer 170. The encapsulation portion 300 may be 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 electronic apparatus of
Manufacturing Method
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, and laser-induced thermal imaging. The electron injection layer, the electron transport layer, the emission layer,
the hole transport layer, and/or the hole injection layer may be formed through a solution process. The solution process may include, for example, a spin coating method, an inkjet process, and/or the like.
When layers constituting the hole transport region, an emission layer, and layers constituting 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.
In the case of using an inkjet, an inkjet printer used for the inkjet may be any suitable inkjet printer generally used in the art.
When each of the electron injection layer, the electron transport layer, the emission layer, and the hole injection layer is formed by spin coating, the spin coating may be performed at a coating speed of about 2,000 rpm to about 5,000 rpm and at a heat treatment temperature of about 80° C. to 200° C. depending on a material to be included in a layer to be formed and the structure of a layer to be formed.
Definition of at Least Some of the Terms
The term “C3-C60 carbocyclic group,” as used herein, refers to a cyclic group consisting of carbon only as a ring-forming atom 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, a heteroatom as a ring-forming atom. The C3-C60 carbocyclic group and the C1-C60 heterocyclic group may each be a monocyclic group consisting of one ring or a polycyclic group in which two or more rings are condensed together with each other. For example, the C1-C60 heterocyclic group has 3 to 61 ring-forming atoms.
The term “cyclic group,” as used herein, may include 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 C3-C60 carbocyclic group may be i) a group T1 or ii) a condensed cyclic group in which two or more groups T1 are condensed together with each other (for example, a cyclopentadiene group, an adamantane group, a norbornane group, a benzene group, a pentalene group, a naphthalene group, an azulene group, an indacene group, an acenaphthylene group, a phenalene group, a phenanthrene group, an anthracene group, a fluoranthene group, a triphenylene group, a pyrene group, a chrysene group, a perylene group, a pentaphene group, a heptalene group, a naphthacene group, a picene group, a hexacene group, a pentacene group, a rubicene group, a coronene group, an ovalene group, an indene group, a fluorene group, a spiro-bifluorene group, a benzofluorene group, an indenophenanthrene group, or an indenoanthracene group),
The terms “the cyclic group,” “the C3-C60 carbocyclic group,” “the C1-C60 heterocyclic group,” “the 7 electron-rich C3-C60 cyclic group,” or “the π electron-deficient nitrogen-containing C1-C60 cyclic group,” as used herein, refer to a group condensed to any suitable 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, 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 divalent 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 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 examples thereof 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 substantially 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 at a main chain (e.g., in the middle) or at a terminal end (e.g., the terminus) of the C2-C60 alkyl group, and examples thereof include an ethenyl group, a propenyl group, and a butenyl group. The term “C2-C60 alkenylene group,” as used herein, refers to a divalent group having substantially 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 at a main chain (e.g., in the middle) or at a terminal end (e.g., the terminus) of the C2-C60 alkyl group, and examples thereof 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 substantially 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 include a methoxy group, an ethoxy group, and an isopropyloxy group.
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 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, and a bicyclo[2.2.2]octyl group. The term “C3-C10 cycloalkylene group,” as used herein, refers to a divalent group having substantially 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 include a 1,2,3,4-oxatriazolidinyl group, a tetrahydrofuranyl group, and a tetrahydrothiophenyl group. The term “C1-C10 heterocycloalkylene group,” as used herein, refers to a divalent group having substantially 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 (e.g., is not aromatic), and examples thereof include a cyclopentenyl group, a cyclohexenyl group, and a cycloheptenyl group. The term “C3-C10 cycloalkenylene group,” as used herein, refers to a divalent group having substantially 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-C10 heterocycloalkenyl group include a 4,5-dihydro-1,2,3,4-oxatriazolyl group, a 2,3-dihydrofuranyl group, and a 2,3-dihydrothiophenyl group. The term “C1-C10 heterocycloalkenylene group,” as used herein, refers to a divalent group having substantially 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 a carbocyclic aromatic system of 6 to 60 carbon atoms. Examples of the C6-C60 aryl group 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, and an ovalenyl group. When the C6-C60 aryl group and the C6-C60 arylene group each include two or more rings, the rings may be condensed together 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 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. Examples of the C1-C60 heteroaryl group 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 include two or more rings, the rings may be condensed together 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 (e.g., is not aromatic when considered as a whole). Examples of the monovalent non-aromatic condensed polycyclic group include an indenyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, an indenophenanthrenyl group, and an indeno anthracenyl group. The term “divalent non-aromatic condensed polycyclic group,” as used herein, refers to a divalent group having substantially 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 non- aromaticity in its entire molecular structure (e.g., is not aromatic when considered as a whole). Examples of the monovalent non-aromatic condensed heteropolycyclic group include a pyrrolyl group, a thiophenyl group, a furanyl group, an indolyl group, a benzoindolyl group, a naphtho indolyl 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 indenocarbazolyl 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 substantially the same structure as the monovalent non-aromatic condensed heteropolycyclic group described above.
The term “C6-C60 aryloxy group,” as used herein, indicates -OA102 (wherein A102 is the C6-C60 aryl group), and the term “C6-C60 arylthio group,” as used herein, indicates -SA103 (wherein A103 is the C6-C60 aryl group).
The term “C7-C60 arylalkyl group,” as used herein, refers to -A104A105 (where A104 may be a C1-C54 alkylene group, and A105 may be a C6-C59 aryl group), and the term “C2-C60 heteroarylalkyl group,” as used herein, refers to -A106A107 (where A106 may be a C1-C59 alkylene group, and A107 may be a C1-C59 heteroaryl group).
The term “R10a,” as used herein, refers to:
a C3-C60 carbocyclic group, a C1-C60 heterocyclic group, a C6-C60 aryloxy group, a C6-C60 arylthio group, a C7-C60 arylalkyl group, or a C2-C60 heteroarylalkyl group, each unsubstituted or substituted with 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, a C1-C60 heterocyclic group, a C6-C60 aryloxy group, a C6-C60 arylthio group, a C7-C60 arylalkyl group, a C2-C60 heteroarylalkyl group, —Si(Q21)(Q22)(Q23), —N(Q21)(Q22), —B(Q21)(Q22), —C(═O)(Q21), —S(═O)2(Q21), —P(═O)(Q21)(Q22), or any combination thereof; or —Si(Q31)(Q32)(Q33), —N(Q31)(Q32), —B(Q31)(Q32), —C(═O)(Q31), —S(═O)2(Q31), or —P(═O)(Q31)(Q32).
In the present specification, Q1 to Q3, Q11 to Q13, Q21 to Q23, and Q31 to Q33 may each independently be: hydrogen; deuterium; —F; —CI; —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; or a C1-C60 alkoxy group; or
The term “heteroatom,” as used herein, refers to any atom other than a carbon atom. Examples of the heteroatom include O, S, N, P, Si, B, Ge, Se, and any combinations thereof.
The term “the third-row transition metal,” as used herein, includes hafnium (Hf), tantalum (Ta), tungsten (W), rhenium (Re), osmium (Os), iridium (Ir), platinum (Pt), gold (Au), etc.
“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.” In other words, 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”. In other words, the “terphenyl group” is a substituted phenyl group having, as a substituent, a C6-C60 aryl group substituted with a C6-C60 aryl group.
The maximum number of carbon atoms in this substituent definition section is an example only. In an embodiment, the maximum carbon number of 60 in the C1-C60 alkyl group is an example, and the definition of the alkyl group is equally applied to a C1-C20 alkyl group. The same applies to other cases.
* and *′, as used herein, unless defined otherwise, each refer to a binding site to a neighboring atom in a corresponding formula.
Hereinafter, a light-emitting device according to embodiments will be described in more detail with reference to Examples.
Example 1
An 15 Ω/cm2 (800 Å) ITO glass substrate (a product of Corning Inc.) was cut to a size of 50 mm×50 mm×0.7 mm, sonicated with isopropyl alcohol and pure water each for 5 minutes, and then cleaned by exposure to ultraviolet rays and ozone for 15 minutes. The resultant glass substrate was loaded onto a vacuum deposition apparatus.
The ITO cathode of the glass substrate was spin-coated with 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) and a heat treatment was performed thereon at 200° C. for 30 minutes to thereby form an electron transport layer having a thickness of 300 Å.
Then, the electron transport layer was spin-coated with a mixture of ZnSeTe/ZnSe/ZnS quantum dot (EVBM=−5.6 eV, ECBM=−2.9 eV) (VBM: valance band maximum, CBM: conduction band minimum) and an n-type Compound SPPO13 (2,7-Bis(diphenylphosphoryl)-9,9′-spirobifluorene, EHOMO=−5.9 eV, ELUMO=−2.6 eV) [0.01 wt %], and a heat treatment was performed thereon at 80° C. for 30 minutes in a nitrogen atmosphere to thereby form a second emission layer having a thickness of 140 Å.
Then, the second emission layer was spin-coated with a mixture of a ZnSeTe/ZnSe/ZnS quantum dot (EVBM=−6.0 eV, ECBM=−2.9 eV) and a p-type Compound CBP(4,4′-Bis(carbazol-9-yl)biphenyl) (EHOMO=−5.8 eV, ELUMO=−2.5 eV) [0.05 wt %], and a heat treatment was performed thereon at 80° C. for 30 minutes in a nitrogen atmosphere to thereby form a first emission layer having a thickness of 280 Å.
The first emission layer was spin-coated with Compound 401 and a heat treatment was performed thereon at 150° C. for 30 minutes to thereby form a hole transport layer having a thickness of 300 Å.
Subsequently, after the glass substrate was mounted on a substrate holder of a vacuum deposition apparatus, HATCN was deposited on the hole transport layer to form a hole injection layer having a thickness of 50 Å, and Al was deposited on the hole injection layer to form an anode having a thickness of 1,000 Å, thereby completing the manufacture of a quantum dot light-emitting device of an inverted structure. The equipment used for the deposition was a Suicel plus 200 evaporator from Sunic Systems.
401(n=10˜50)
Comparative Examples 1 to 3
Light-emitting devices were manufactured in substantially the same manner as in Example 1 except that the second emission layers and the first emission layers were formed as shown in Table 1. The electron transport layers, the hole transport layers, and the hole injection layers of the light-emitting devices were manufactured in the same manner as in Example 1.
To evaluate the characteristics of the light-emitting devices manufactured according to Examples and Comparative Examples, the driving voltage at a current density of 10 mA/cm2, efficiency, lifespan, and the like were measured, and results thereof are shown in Table 3.
The driving voltage and current density of the light-emitting devices were measured using a source meter (2400 series, Keithley Instruments Inc.), and the efficiency and lifespan were measured using C9920-2-12, which is a measurement system of Hamamatsu Photonics Inc.
The HOMO energy level of the p-type compound, the valence band of the first quantum dot, the LUMO energy level of the n-type compound, and the valence band of the second quantum dot are shown in Table 2.
Referring to Table 3, it can be seen that the devices of the Examples had lower driving voltage and improved efficiency and lifespan than the devices of the Comparative Examples.
As described above, according to the one more embodiments, a light-emitting device may exhibit improved performance as compared with other devices in the related art.
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 equivalents thereof.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2022-0077806 | Jun 2022 | KR | national |
