Light emitting device, display apparatus, and electronic apparatus

Abstract

Provided are a light emitting device, a display apparatus, and an electronic apparatus. The light emitting device includes: a first electrode; a second electrode; an emission layer between the first electrode and the second electrode; and an electron transport region between the emission layer and the second electrode. The electron transport region includes a first electron transport layer on the emission layer and a second electron transport layer on the first electron transport layer. The first electron transport layer includes first particles, and the second electron transport layer includes second particles having an average particle diameter smaller than an average particle diameter of the first particles.

Description

Technical Field

[0001] The embodiments disclosed in this application relate to light-emitting devices, methods for manufacturing the light-emitting devices, display devices, and electronic devices. Background Technology

[0002] Recently, with the development of mobile devices such as smartphones and tablet computers, and media devices such as computers and TVs, various display devices have been developed for use with these mobile devices and media devices.

[0003] Display devices may include self-emissive light-emitting devices capable of emitting light through luminescent materials to provide images that are visually recognizable from the outside.

[0004] The light-emitting device may include transport regions for holes and electrons supplied from electrodes, and the transport regions may be placed between electrodes facing each other.

[0005] However, interpenetration and / or mixing between materials may occur in such luminescent materials, leading to a reduction in luminescence efficiency and lifetime properties. Summary of the Invention

[0006] According to this disclosure, a light-emitting device with improved luminous efficiency and improved lifetime properties is provided.

[0007] According to this disclosure, a method for manufacturing a light-emitting device having improved luminous efficiency and improved lifetime properties is provided.

[0008] According to an aspect of this disclosure, a display device is provided that provides improved image quality.

[0009] According to aspects of this disclosure, an electronic device including a light-emitting device or a display device is provided.

[0010] The light-emitting device may include a first electrode, a second electrode, an emitting layer between the first and second electrodes, and an electron transport region between the emitting layer and the second electrode. The electron transport region may include a first electron transport layer on the emitting layer and a second electron transport layer on the first electron transport layer. The first electron transport layer may include first particles, and the second electron transport layer may include second particles having an average particle size smaller than that of the first particles.

[0011] In some embodiments, the average particle size of the first particle can be in the range of 5 nm to 20 nm.

[0012] In some embodiments, the average particle size of the first particle can be in the range of 5 nm to 10 nm.

[0013] In some embodiments, the average particle size of the second particle can be in the range of 2 nm to 4 nm.

[0014] In some embodiments, the average particle size of the second particle can be in the range of 3 nm to 4 nm.

[0015] In some embodiments, the electron transport region may further include a third electron transport layer on the second electron transport layer, and the third electron transport layer may include third particles having an average particle size larger than that of the second particles.

[0016] In some embodiments, the first particle, the second particle, and the third particle may comprise the same material.

[0017] In some embodiments, the average particle size of the third particle can be in the range of 5 nm to 20 nm.

[0018] In some embodiments, the emitter layer may include quantum dots.

[0019] In some embodiments, the average particle size of the quantum dots can be in the range of 5 nm to 15 nm.

[0020] In some embodiments, the average particle size of the quantum dots may be equal to or less than the average particle size of the first particle.

[0021] In some embodiments, the electron transport region may further include an electron injection layer between the second electron transport layer and the second electrode.

[0022] In some embodiments, the light-emitting device may further include a hole transport region between the first electrode and the emitting layer.

[0023] In some embodiments, the hole transport region may further include a hole injection layer on the first electrode and a hole transport layer on the hole injection layer.

[0024] In some embodiments, both the first and second particles may comprise a compound selected from ZnMgO, Li2O, BaO, LiF, NaCl, CsF, RbCl, RbI, CuI, KI, metal acetates, metal benzoates, anthracene compounds, Alq3 (tris(8-hydroxyquinoline)aluminum), 1,3,5-tris[(3-pyridyl)-benzene-3-yl]benzene, 2,4,6-tris(3'-(pyridyl)biphenyl-3-yl)-1,3,5-triazine, 2-(4-(N-phenylbenzimidazol-1-yl)phenyl)-9,10-dinaphthylanthracene, TPBi (1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene), BCP (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline), Bp At least one of the following groups: hen (4,7-diphenyl-1,10-phenanthroline), TAZ (3-(4-biphenyl)-4-phenyl-5-tert-butylphenyl-1,2,4-triazole), NTAZ (4-(naphthyl-1-yl)-3,5-diphenyl-4H-1,2,4-triazole), tBu-PBD (2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole), BAlq (bis(2-methyl-8-hydroxyquinoline-N1,O8)-(1,1'-biphenyl-4-hydroxy)aluminum), Bebq2 (bis(10-hydroxybenzo[h]quinoline)beryllium), ADN (9,10-bis(naphthyl-2-yl)anthracene), and BmPyPhB (1,3-bis[3,5-bis(pyridin-3-yl)phenyl]benzene).

[0025] The display device may include a substrate, a circuit layer on the substrate, and a light-emitting device electrically connected to the circuit layer. The light-emitting device may include a first electrode, a second electrode, an emitting layer between the first and second electrodes, and an electron transport region between the emitting layer and the second electrode. The electron transport region may include a first electron transport layer on the emitting layer and a second electron transport layer on the first electron transport layer. The first electron transport layer may include first particles, and the second electron transport layer may include second particles having an average particle size smaller than that of the first particles.

[0026] In some embodiments, the emitting layer may include quantum dots, and the circuit layer may include transistors connected to a first electrode of the light-emitting device.

[0027] The electronic device may include the aforementioned display device, memory, and processor for executing data included in the memory related to controlling the operation of the display device.

[0028] In a method of manufacturing a light-emitting device, an emitting layer may be formed on a first electrode. The method may include forming a first electron transport layer comprising first particles on the emitting layer by inkjet printing. The method may also include forming a second electron transport layer on the first electron transport layer by inkjet printing, wherein the second electron transport layer comprises second particles having an average particle size smaller than the average particle size of the first particles. The method may further include forming a second electrode on the second electron transport layer.

[0029] In some embodiments, the method may include forming a third electron transport layer between the second electron transport layer and the second electrode. The third electron transport layer may include third particles having an average particle size larger than that of the second particles.

[0030] According to an embodiment, the electron transport region included in the light-emitting device may include a first electron transport layer disposed on the emitting layer and including a first particle, and a second electron transport layer disposed on the first electron transport layer and including a second particle. The average particle size (D50) of the second particle may be smaller than the average particle size (D50) of the first particle. Therefore, the first particle having a relatively large average particle size (D50) can suppress the penetration and / or diffusion of the second particle into the emitting layer. Thus, the luminous efficiency, color clarity, and lifetime properties of the light-emitting device can be improved. Attached Figure Description

[0031] Figure 1 This is a schematic cross-sectional view showing a light-emitting device according to an embodiment.

[0032] Figure 2 This is a schematic cross-sectional view showing a light-emitting device according to an embodiment.

[0033] Figure 3 This is a schematic cross-sectional view showing a light-emitting device according to an embodiment.

[0034] Figure 4 This is a schematic cross-sectional view showing a light-emitting device according to an embodiment.

[0035] Figure 5 This is a schematic cross-sectional view showing a light-emitting device according to an embodiment.

[0036] Figure 6 This is a schematic plan view illustrating a display device according to an embodiment.

[0037] Figure 7 This is a schematic cross-sectional view showing a display device according to an embodiment.

[0038] Figure 8 This is a schematic cross-sectional view showing a display device according to an embodiment.

[0039] Figure 9 This is a block diagram of an electronic device according to an embodiment.

[0040] Figure 10 These are schematic diagrams of electronic devices according to various embodiments. Detailed Implementation

[0041] According to embodiments of this disclosure, a light-emitting device is provided, the light-emitting device comprising a first electron transport layer including first particles and a second electron transport layer including second particles. In some aspects, a display device including the light-emitting device is provided.

[0042] In the following description, embodiments of the invention will be described in more detail with reference to the accompanying drawings. The same reference numerals may be used to indicate the same elements in the drawings, and repeated descriptions of the same elements may be omitted. The embodiments disclosed in the drawings are examples and should be understood to include all modifications, equivalents, and substitutions contained within the spirit and scope of the invention.

[0043] The terms “on”, “connected”, “combined”, etc., used herein refer to direct placement / connection / combination, and also to the situation where another element is placed between two different elements.

[0044] The terms “first,” “second,” “below,” “above,” etc., are used in a relative sense to distinguish different elements or positions and do not specify absolute positions or absolute orders.

[0045] As used herein, the terms “about” or “approximately” include the stated value and include the acceptable range of deviation for a particular value, determined by one of ordinary skill in the art taking into account the measurement in question and the error associated with the measurement of the particular quantity. For example, the terms “about” or “approximately” may mean within one or more standard deviations, or within ±30%, ±20%, ±10%, ±5% of the stated value.

[0046] As used herein, the term "substantially" means approximately or actually. The term "substantially equal" means approximately or actually equal. The term "substantially identical" means approximately or actually identical. The term "substantially perpendicular" means approximately or actually perpendicular. The term "substantially parallel" means approximately or actually parallel.

[0047] As used herein, the terms “average particle size (D50)”, “average particle size”, or “D50” may mean that the cumulative percentage of volume in a particle size distribution based on particle volume corresponds to 50% of the particle size.

[0048] In this specification, the term "substituted or unsubstituted" may refer to an unsubstituted group or a group substituted by one or more substituents selected from the group consisting of: for example, deuterium atom, halogen atom, cyano, nitro, amino, silyl, oxygen, thio, sulfinyl, sulfonyl, carbonyl, ester, boron, phosphine oxide, phosphine sulfide, alkyl (e.g., C1-C1), halogen, cyano ...silane, alkyl (e.g., C1-C1), halogen, cyano, silane, alkyl (e.g., C1-C1), alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, 60 C1-C 30 Or C1-C 10 Alkyl), alkenyl (e.g., C2-C) 60 C2-C 30 Or C2-C 10 alkenyl), alkynyl (e.g., C2-C) 60 C2-C 30 Or C2-C 10 alkynyl), alkoxy (e.g., C1-C) 60 C1-C 10 alkoxy), hydrocarbon cycloyl, aryl (e.g., C6-C) 60 Aryl groups and heterocyclic groups (e.g., C1-C) 60 Heterocyclic groups). For example, the term "substituted alkyl" can refer to a group in which at least one of the hydrogen atoms of the alkyl group is replaced by the aforementioned substituent, thereby further bonding the substituent to the carbon atom of the alkyl group.

[0049] Substituents may include combinations selected from the above-described groups. For example, at least one hydrogen atom of the alkyl, aryl, or other above-described groups included as substituents may be replaced by a deuterium atom, halogen atom, cyano, nitro, amino, silyl, oxy, thio, sulfinyl, sulfonyl, carbonyl, ester, boron, phosphine oxide, phosphine sulfide, alkyl, alkenyl, alkynyl, cycloalkyl, aryl, or heterocyclic group.

[0050] Among the substituents, polyvalent substituents (such as amino, phosphine sulfide, phosphine oxide, sulfinyl, sulfonyl, oxygen, carbonyl, ester, etc.) can be C1-C2. 10 Alkyl, C2-C 10 alkenyl, C2-C 10 alkynyl or C6-C 10 Aryl substitution.

[0051] As used herein, the term "substituted or unsubstituted C" a -C b "Y group" refers to the number of carbon atoms in the unsubstituted Y group, and may not include carbon atoms of substituents.

[0052] Alkyl groups are monovalent hydrocarbon groups that have had one hydrogen atom removed from a straight-chain or branched hydrocarbon group. For example, alkyl groups may include methyl, ethyl, propyl, sec-butyl, tert-butyl, isobutyl, pentyl, neopentyl, 2-ethylbutyl, 3,3-dimethylbutyl, hexyl, heptyl, octyl, etc.

[0053] Alkylene can refer to a divalent hydrocarbon group that has two hydrogen atoms removed from a straight-chain or branched hydrocarbon group.

[0054] An alkenyl group can have the same skeleton as an alkyl group and can refer to a monovalent hydrocarbon group with at least one double bond between carbon atoms. An alkenyl group can refer to a divalent hydrocarbon group that further removes one hydrogen atom from an alkenyl group.

[0055] An alkynyl group can have the same skeleton as an alkyl group and can refer to a monovalent hydrocarbon group with at least one triple bond between carbon atoms. An alkynyl group can refer to a divalent hydrocarbon group that has further removed one hydrogen atom from an alkynyl group.

[0056] An aryl group can refer to a monovalent hydrocarbon group that has a hydrocarbon structure with one hydrogen atom removed. An aryl group can include groups with multiple aromatic rings directly linked, such as biphenyl. Aryl groups can include, for example, phenyl, naphthyl, anthraceneyl, phenanthryl, pyrene, fluorenyl, tetraphenyl, biphenyl, terphenyl, tetraphenyl, alkyl, etc.

[0057] Groups in which two or more aromatic rings are condensed / linked together by aliphatic cyclic hydrocarbon rings (such as fluorenyl) can be included in the aryl category.

[0058] For example, biphenyl can be interpreted as aryl or phenyl groups substituted with phenyl groups.

[0059] A aryl group can refer to a divalent hydrocarbon group that has one hydrogen atom removed from an aryl group.

[0060] A heteroaryl group can refer to a monovalent group having an aromatic structure and including at least one heteroatom (such as B, O, P, S, and Si) in the cyclic atom. A heteroaryl group can refer to a divalent group having an aromatic structure and including at least one heteroatom (such as B, O, P, S, and Si) in the cyclic atom. In examples where a heteroaryl or heteroaryl group includes two or more heteroatoms, the two or more heteroatoms may be the same as or different from each other.

[0061] Structures in which two or more aromatic rings are condensed / linked by non-aromatic heterocyclic groups (such as carbazole groups) can also be included in the heteroaryl category.

[0062] Figure 1 This is a schematic cross-sectional view showing a light-emitting device according to an embodiment.

[0063] Reference Figure 1The light-emitting device 100 may include a first electrode 110, an emitting layer 130, an electron transport region 140, and a second electrode 150 stacked in sequence.

[0064] In an embodiment, the hole transport region 120 may be further disposed between the first electrode 110 and the emitter layer 130.

[0065] The first electrode 110 may be an anode. In some embodiments, the first electrode 110 may be used as an anode and may also be used as a pixel electrode. In this case, the first electrode 110 may include a high work function conductive material that facilitates hole injection.

[0066] The first electrode 110 can be configured as a transmission electrode. The first electrode 110 may include a transparent conductive oxide, such as indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium tin zinc oxide (ITZO), etc.

[0067] The first electrode 110 can be configured as a semi-transparent electrode or a reflective electrode. The first electrode 110 may comprise one metal selected from Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF, Mo, Ti, W, In, Sn, and Zn, or an alloy of two or more of these metals. For example, the first electrode 110 may comprise a mixture of Li, Ca, LiF / Ca (a stacked structure of LiF and Ca), LiF / Al (a stacked structure of LiF and Al), and Ag and Mg.

[0068] The first electrode 110 may have a single-layer structure or a multi-layer structure. For example, the first electrode 110 may have a three-layer structure of ITO / Ag / ITO.

[0069] The thickness of the first electrode 110 can be in the range of about 700 Å to about 10,000 Å or about 1,000 Å to about 3,000 Å.

[0070] The second electrode 150 can be used as a cathode. In some embodiments, the second electrode 150 can be used as an electron injection electrode or a cathode. The second electrode 150 may include a metal, alloy, conductive compound, or other material having a low work function.

[0071] For example, 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, etc. They can be used alone or in combination of two or more of them.

[0072] The second electrode 150 can be configured as a transmission electrode, a semi-transparent electrode, or a reflection electrode. The second electrode 150 can have a single-layer structure or a multi-layer structure.

[0073] The emitting layer 130 can be configured as the display layer of the light-emitting device 100.

[0074] In one embodiment, the emitter layer 130 may include quantum dots 132.

[0075] Quantum dot 132 may include a material that emits light when excited by light or an electric field. For example, quantum dot 132 may receive energy from the outside and reach an excited state, and may emit energy (e.g., light) according to the band gap of quantum dot 132.

[0076] For example, quantum dot 132 may include group II-VI compounds, group III-V compounds, group IV-VI compounds, group IV elements or compounds including them, and mixtures thereof. These may be used alone or in combination of two or more of them.

[0077] Group II-VI compounds can be selected from the group consisting of binary, ternary, and quaternary compounds. Binary compounds are selected from CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, MgSe, MgS, and mixtures thereof; ternary compounds are selected from CdSeS, CdSeTe, CdSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdH gSe, CdHgTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, HgZnS, HgZnSe, HgZnTe and mixtures thereof; the quaternary compound is selected from CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, HgZnSTe and mixtures thereof.

[0078] III-V group compounds can be selected from the group consisting of binary, ternary and quaternary compounds. The binary compounds are selected from GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb and mixtures thereof. The ternary compounds are selected from GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb and mixtures thereof. The quaternary compounds are selected from GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, InAlPSb, GaAlNP and mixtures thereof.

[0079] Group IV-VI compounds can be selected from the group consisting of binary, ternary, and quaternary compounds. The binary compounds are selected from SnS, SnSe, SnTe, PbS, PbSe, PbTe, and mixtures thereof. The ternary compounds are selected from SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, and mixtures thereof. The quaternary compounds are selected from SnPbSSe, SnPbSeTe, SnPbSTe, and mixtures thereof.

[0080] Group IV elements or compounds including them may include Si, Ge, SiC, SiGe and mixtures thereof.

[0081] In some embodiments, the quantum dot 132 may have a homogeneous single structure, a core-shell structure, a gradient structure, or a hybrid structure thereof.

[0082] In some embodiments, the quantum dot 132 may have a core-shell structure. The core may be the fundamental part that enables light emission. The shell can prevent oxidation of the core and reduce the trapping energy level on the surface of the core, thereby improving the stability and efficiency of the core. The shell may include inorganic oxides or semiconductor compounds. Semiconductor compounds may include CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnSeS, ZnTeS, GaAs, GaP, GaSb, HgS, HgSe, HgTe, InAs, InP, InGaP, InSb, AlAs, AlP, or AlSb, etc.

[0083] For example, the color of emitted light can be adjusted based on the particle size of quantum dot 132. Quantum dot 132 can be classified as blue quantum dots, red quantum dots, or green quantum dots, etc.

[0084] In some embodiments, the quantum dot 132 can emit blue, red, or green light. Therefore, a separate color filter or backlight may not be required in the display device. Consequently, the thickness of the light-emitting device 100 or the display device / electronic device using the light-emitting device 100 can be reduced, and production costs can be lowered.

[0085] In some embodiments, the average particle size (D50) of the quantum dot 132 can be in the range of 5 nm to 15 nm, and in another embodiment, it can be in the range of 8 nm to 12 nm. Within these ranges, luminous efficiency and color clarity can be improved.

[0086] In some embodiments, the emitting layer 130 may include a host material excited by holes and electrons, and a dopant material for improving luminescence efficiency through energy absorption and emission.

[0087] In this embodiment, the emitting layer 130 can be patterned independently for each of the red, green, and blue light-emitting devices to generate different colors of light for each device. For example, the emitting layer 130 can be patterned as a red emitting layer, a green emitting layer, and a blue emitting layer corresponding to each light-emitting device.

[0088] In this embodiment, the emitting layer 130 may not be patterned for each light-emitting device and may be provided publicly for multiple light-emitting devices. For example, the emitting layer 130 may emit white light, and the color of each device may be achieved through a color filter.

[0089] The host material may include a host, a fluorescent host, or a combination thereof for use in phosphorescent devices. For example, host materials may include BCPDS (bis(4-(9H-carbazole-9-yl)phenyl)diphenylsilane), POPCPA ((4-(1-(4-(diphenylamino)phenyl)cyclohexyl)phenyl)diphenylphosphine oxide), DPEPO (bis[2-(diphenylphosphino)phenyl] ether oxide), mCBP (3,3'-bis(9H-carbazole-9-yl)-1,1'-biphenyl), CBP (4,4'-bis(N-carbazole)-1,1'-biphenyl), mCP (1,3-bis(carbazole-9-yl)phenyl), PPF (2,8-bis(diphenylphosphino)dibenzo[b,d]furan), and TCTA (4,4',4''-tris(carbazole-9-yl)triphenylamine). TPBi (1,3,5-tris(1-phenyl-1H-benzis[d]imidazol-2-yl)benzene), Alq3 (tris(8-hydroxyquinoline)aluminum), ADN (9,10-di(naphthyl-2-yl)anthracene), TBADN (2-tert-butyl-9,10-di(naphthyl-2-yl)anthracene), DSA (stilbeneyl arylene), CDBP (4,4'-bis(9-carbazolyl)-2,2'-dimethylbiphenyl), MADN (2-methyl-9,10-bis(naphthyl-2-yl)anthracene), CP1 (hexaphenylcyclotriphosphazene), UGH2 (1,4-bis(triphenylsilyl)benzene), DPSiO3 (hexaphenylcyclotrisiloxane), DPSiO4 (octaphenylcyclotetrasiloxane), etc.

[0090] Dopant materials may include phosphorescent dopants, fluorescent dopants, or combinations thereof. For example, dopant materials may include metal complexes containing iridium (Ir), platinum (Pt), osmium (Os), gold (Au), titanium (Ti), zirconium (Zr), hafnium (Hf), europium (Eu), terbium (Tb), or thulium (Tm); or BCzVB (1,4-bis[2-(3-N-ethylcarbazolyl)vinyl]benzene), DPAVB (4-(di-p-tolylamino)-4'-[(di-p-tolylamino)styryl]benzene), N-BDAVBi (N-(4-((E)-2-(6-(((E)-4-(diphenylamino)styryl)naphth-2-yl)vinyl)phenyl)-N-phenylaniline), DPAVBi (4,4'-bis[2-(4-(N,N-diphenylamino)phenyl)vinyl]biphenyl), TBP (2,5,8,11-tetratert-butylperylene), or combinations thereof.

[0091] In an embodiment, the thickness of the emitting layer 130 can be in the range of about 100 Å to about 1000 Å, about 100 Å to about 800 Å, about 200 Å to about 800 Å, or about 200 Å to about 600 Å. Within the above range, the luminous efficiency and lifetime of the light-emitting device 100 can be further improved.

[0092] In an embodiment, the electron transport region 140 may include a first electron transport layer 142 and a second electron transport layer 144. The first electron transport layer 142 may be disposed on the emission layer 130 and may include a first particle 141. The second electron transport layer 144 may be disposed on the first electron transport layer 142 and may include a second particle 143.

[0093] In this embodiment, the first electron transport layer 142 can be directly disposed on the emission layer 130.

[0094] In this embodiment, the second electron transport layer 144 can be directly disposed on the first electron transport layer 142.

[0095] The average particle size (D50) of the second particle 143 can be smaller than that of the first particle 141. Therefore, the first particle 141, which has a relatively large D50, can suppress the penetration and / or diffusion of the second particle 143 into the emitting layer 130. As a result, the luminous efficiency, color clarity, and lifetime properties of the light-emitting device 100 can be improved.

[0096] In the example where the quantum dot 132 is used as the luminescent material of the emitting layer 130, the emitting layer 130 and the electron transport region 140 can be formed by an inkjet printing process. In this case, some particles included in the electron transport region 140 may penetrate and / or diffuse into the emitting layer 130 with the ink droplets, thereby reducing luminous efficiency and lifetime properties.

[0097] According to an embodiment of the present invention, the first particle 141 having a relatively large D50 can be used as a barrier between the emitting layer 130 and the electron transport region 140, thereby suppressing the aforementioned interlayer penetration and / or diffusion. Therefore, the luminous efficiency and lifetime properties of the light-emitting device 100 can be improved.

[0098] In an embodiment, the D50 of the quantum dot 132 may be greater than or equal to the D50 of the first particle 141. In this case, the D50 of the first particle 141 may be large enough that the first particle 141 can suppress penetration and / or diffusion between the described emission layer 130 and the electron transport region 140.

[0099] In an embodiment, the D50 of quantum dot 132 may be equal to or less than the D50 of the first particle 141. Therefore, penetration and / or diffusion can be further physically prevented.

[0100] In some embodiments, the D50 of the first particle 141 can be in the range of 5 nm to 20 nm, and in another embodiment, it can be in the range of 5 nm to 10 nm. Within this range, the second particle 143 can be further prevented from penetrating and / or diffusing into the light-emitting layer 130.

[0101] In some embodiments, the D50 of the second particle 143 can be in the range of 2 nm to 4 nm, and in another embodiment, it can be in the range of 3 nm to 4 nm. Within this range, the electron mobility from the second electrode 150 can be maintained or improved. Therefore, the luminous efficiency of the light-emitting device 100 can be further improved.

[0102] Figure 2 This is a schematic cross-sectional view showing a light-emitting device according to an embodiment.

[0103] Reference Figure 2 The electron transport region 140 may further include a third electron transport layer 146 disposed on the second electron transport layer 144 and including a third particle 145.

[0104] In this embodiment, the third electron transport layer 146 can be directly disposed on the second electron transport layer 144.

[0105] In an embodiment, the third electron transport layer 146 may be placed between the second electron transport layer 144 and the second electrode 150.

[0106] The D50 of the third particle 145 can be greater than that of the second particle 143. Therefore, the penetration and / or diffusion of the second particle 143 into the second electrode 150 can be suppressed. Thus, the lifetime properties and luminous efficiency of the light-emitting device 100 can be further improved.

[0107] In some embodiments, the D50 of the third particle 145 can be in the range of 5 nm to 20 nm, and in another embodiment, it can be in the range of 5 nm to 10 nm. Within this range, it can further prevent particles included in the electron transport region 140 from penetrating and / or diffusing into the second electrode 150.

[0108] In this embodiment, the hole transport region 120 may be disposed between the first electrode 110 and the emitter layer 130. The hole transport region 120 may have a single-layer structure or a multi-layer structure comprising multiple layers of different materials.

[0109] Figure 3 This is a schematic cross-sectional view showing a light-emitting device according to an embodiment.

[0110] Reference Figure 3 The electron transport region 140 may further include an electron injection layer 147 disposed between the second electron transport layer 144 and the second electrode 150. In some embodiments, the electron injection layer 147 may be disposed between the third electron transport layer 146 and the second electrode 150.

[0111] The hole transport region 120 may include a hole injection layer 122 disposed on the first electrode 110 and a hole transport layer 124 disposed on the hole injection layer 122. For example, the hole injection layer 122 and the hole transport layer 124 may be stacked sequentially in the direction from the first electrode 110 to the emitter layer 130.

[0112] Figure 4 This is a schematic cross-sectional view showing a light-emitting device according to an embodiment.

[0113] Reference Figure 4 The electron transport region 140 may further include a hole blocking layer 148 disposed between the emitter layer 130 and the first electron transport layer 142. The injection of holes from the hole transport region 120 can be suppressed or blocked by the hole blocking layer 148. Therefore, the emission energy and luminous efficiency of the emitter layer 130 can be further improved.

[0114] In some embodiments, the penetration or diffusion of the second particle 143 into the hole blocking layer 148 and / or the emitting layer 130 can be suppressed by the first electron transport layer 142. Therefore, the lifetime and luminescent properties of the light-emitting device 100 can be improved, while the hole-blocking performance of the hole blocking layer 148 is enhanced.

[0115] For example, electron transport region 140 may include a compound represented by the chemical formula ET.

[0116]

[0117] In the chemical formula ET, X 1 To X 3 At least one of them can be N, and the rest can each be CR independently. a R a It can be a hydrogen atom, a deuterium atom, or a substituted or unsubstituted C1-C atom. 20 Alkyl, substituted or unsubstituted C6-C 60 aryl or substituted or unsubstituted C2-C 60 Mixed aromatic compounds.

[0118] When X 1 To X 3 When one of them is N, a compound represented by the chemical formula ET may include a pyridine group. In X 1 To X 3 In the two examples where N is present, compounds represented by the chemical formula ET may include a pyrimidine group. In X... 1 To X 3 In the examples where all elements are N, compounds represented by the chemical formula ET may include triazine groups.

[0119] a, b, and c can each be an integer from 0 to 10 independently. L1 To L 3 Each can be an independent direct bond, substituted or unsubstituted C6-C. 30 aryl or substituted or unsubstituted C2-C 30 Hybrid aryl.

[0120] When a, b, and c are integers of 2 or greater, multiple L 1 L 2 or L 3 For example, they are directly linked through carbon atoms in each aromatic ring (e.g., sp2 carbons), and can all be independently substituted or unsubstituted C6-C atoms. 30 aryl or substituted or unsubstituted C2-C 30 Hybrid aryl.

[0121] Ar 1 To Ar 3 Each can be an independent hydrogen atom, deuterium atom, substituted or unsubstituted C1-C atom. 20 Alkyl, substituted or unsubstituted C6-C 30 aryl or substituted or unsubstituted C2-C 30 Mixed aryl groups. For example, Ar 1 To Ar 3 They can all be independently substituted or unsubstituted phenyl groups, substituted or unsubstituted carbazolyl groups, or substituted or unsubstituted fluorenyl groups.

[0122] Non-limiting examples of compounds represented by the chemical formula ET are as follows.

[0123]

[0124]

[0125]

[0126]

[0127] The electron transport region 140 may also include compounds ET11 and ET12.

[0128]

[0129] For example, electron transport region 140 may include anthracene compounds, Alq3 (tris(8-hydroxyquinoline)aluminum), 1,3,5-tris[(3-pyridyl)-benzene-3-yl]benzene, 2,4,6-tris(3'-(pyridin-3-yl)biphenyl-3-yl)-1,3,5-triazine, 2-(4-(N-phenylbenzimidazol-1-yl)phenyl)-9,10-dinaphthylanthracene, TPBi (1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene), BCP (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline), Bphen (4,7-diphenyl-1,10-phenanthroline), TAZ (3-( 4-Biphenyl)-4-phenyl-5-tert-butylphenyl-1,2,4-triazole, NTAZ (4-(naphthyl-1-yl)-3,5-diphenyl-4H-1,2,4-triazole), tBu-PBD (2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole), BAlq (bis(2-methyl-8-hydroxyquinoline-N1,O8)-(1,1'-biphenyl-4-hydroxy)aluminum), Bebq2 (bis(10-hydroxybenzo[h]quinoline)beryllium), ADN (9,10-bis(naphthyl-2-yl)anthracene), BmPyPhB (1,3-bis[3,5-bis(pyridin-3-yl)phenyl]benzene), etc. These compounds can be used alone or in combination of two or more.

[0130] The aforementioned material may be included in at least one of the electron injection layer 147, the first electron transport layer 142, the second electron transport layer 144, the third electron transport layer 146, and the hole blocking layer 148.

[0131] The electron transport region 140 may include alkali metals, alkaline earth metals, rare earth metals, alkali metal compounds, alkaline earth metal compounds, rare earth metal compounds, alkali metal complexes, alkaline earth metal complexes, rare earth metal complexes, or combinations thereof. In an embodiment, the above materials may be included in the electron injection layer 147.

[0132] Alkali metals may include Li, Na, K, Rb, Cs, or any combination thereof. Alkali earth metals may include Mg, Ca, Sr, Ba, or any combination thereof. Rare earth metals may include Sc, Y, Ce, Tb, Yb, Gd, or any combination thereof.

[0133] Alkali metal compounds, alkaline earth metal compounds, and rare earth metal compounds may respectively include oxides, halides (e.g., fluorides, chlorides, bromides, iodides, or other halides), tellurides, or combinations thereof of alkali metals, alkaline earth metals, and rare earth metals.

[0134] Alkali metal complexes, alkaline earth metal complexes, and rare earth metal complexes may include the metal ions of the aforementioned alkali metal, alkaline earth metal, or rare earth metal, as well as ligands bound to the metal ions. Ligands may include, for example, hydroxyquinoline, hydroxyisoquinoline, hydroxybenzoquinoline, hydroxyacridine, hydroxyphenanthridine, hydroxyphenyloxazole, hydroxyphenylthiazole, hydroxyphenyloxadiazole, hydroxyphenylthiadiazole, hydroxyphenylpyridine, hydroxyphenylbenzimidazole, hydroxyphenylbenzothiazole, bipyridine, phenanthrene, cyclopentadiene, or combinations thereof.

[0135] In some embodiments, the first particle 141, the second particle 143, and / or the third particle 145 may include ZnMgO, Li2O, BaO, LiF, NaCl, CsF, RbCl, RbI, CuI, KI, metal acetates, metal benzoates, anthracene compounds, Alq3 (tris(8-hydroxyquinoline)aluminum), 1,3,5-tris[(3-pyridyl)benzene-3-yl]benzene, 2,4,6-tris(3'-(pyridyl)biphenyl-3-yl)-1,3,5-triazine, 2-(4-(N-phenylbenzimidazol-1-yl)phenyl)-9,10-dinaphthylanthracene, TPBi (1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene), BCP (2,9-dimethyl-4,7-diphenyl-1, 10-Phenanthroline), Bphen (4,7-diphenyl-1,10-phenanthroline), TAZ (3-(4-biphenyl)-4-phenyl-5-tert-butylphenyl-1,2,4-triazole), NTAZ (4-(naphthyl-1-yl)-3,5-diphenyl-4H-1,2,4-triazole), tBu-PBD (2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole), BAlq (bis(2-methyl-8-hydroxyquinoline-N1,O8)-(1,1'-biphenyl-4-hydroxy)aluminum), Bebq2 (bis(10-hydroxybenzo[h]quinoline)beryllium), ADN (9,10-bis(naphthyl-2-yl)anthracene), BmPyPhB (1,3-bis[3,5-bis(pyridin-3-yl)phenyl]benzene), etc. These compounds can be used alone, or in combination of two or more of them.

[0136] In an embodiment, the first particle 141, the second particle 143, and / or the third particle 145 may include ZnMgO.

[0137] The thickness of the electron transport region 140 can range from about 100 Å to about 1,000 Å (e.g., about 150 Å to about 500 Å). In an example where the electron transport region 140 includes an electron injection layer 147, a first electron transport layer 142, a second electron transport layer 144, and a third electron transport layer 146, the thickness of the electron injection layer 147 can range from about 1 Å to about 100 Å, from about 1 Å to about 90 Å, or from about 5 Å to about 50 Å, and the sum of the thicknesses of the first electron transport layer 142, the second electron transport layer 144, and the third electron transport layer 146 can range from about 10 Å to about 900 Å, from about 10 Å to about 500 Å, or from about 100 Å to about 400 Å.

[0138] Within the aforementioned thickness range, the electron injection and electron transport properties can be further improved without excessively increasing the driving voltage, and the stability of the electron transport region 140 can be improved.

[0139] Each layer of the electron transport region 140 can be formed by processes such as vacuum deposition, spin coating, inkjet printing, laser printing, casting, and laser thermal transfer.

[0140] In this embodiment, each layer of the electron transport region 140 can be formed by inkjet printing. For example, the first electron transport layer 142, the second electron transport layer 144, and / or the third electron transport layer 146 can be formed by inkjet printing.

[0141] In the example where quantum dot 132 is used as the luminescent material of emitting layer 130, large-area emission patterns can be fabricated in a short time using inkjet printing. As described herein, multiple layers comprising particles with different D50s (i.e., first electron transport layer 142, second electron transport layer 144, and third electron transport layer 146) can be arranged by inkjet printing, and interlayer penetration and / or diffusion as described herein can be suppressed. Therefore, luminescent efficiency and lifetime properties can be improved while increasing production efficiency.

[0142] like Figure 4 As shown, the hole transport region 120 may include a hole injection layer 122, a hole transport layer 124, and an electron blocking layer 126 sequentially stacked from the first electrode 110. Electron transfer from the electron transport region 140 to the hole transport region 120 can be blocked by the electron blocking layer 126. Therefore, the generation of excitons in the emission layer 130 can be increased, and the luminescence efficiency can be further improved.

[0143] For example, hole transport region 120 may include a compound represented by the chemical formula HT.

[0144] [Chemical formula HT]

[0145] In the chemical formula HT, L1 and L2 can both be independent straight-chain bonds, substituted or unsubstituted C6-C bonds. 30 aryl or substituted or unsubstituted C2-C 30 Hybrid aryl.

[0146] a and b can both be independent integers from 0 to 10. In examples where a or b is an integer greater than or equal to 2, multiple L1s and multiple L2s are directly connected, for example, by carbon atoms in each aromatic ring (e.g., sp2 carbons), and can both be independently substituted or unsubstituted C6-Cs. 30 aryl or substituted or unsubstituted C2-C 30 Hybrid aryl.

[0147] Ar1 and Ar2 can both be independently substituted or unsubstituted C6-C. 30 aryl or substituted or unsubstituted C2-C 30 Heteroaryl, and Ar3 is a substituted or unsubstituted C6-C. 30 Aryl.

[0148] In the embodiments, the compound represented by the chemical formula HT can be a monoamine compound. In the embodiments, the compound represented by the chemical formula HT can be a diamine compound wherein at least one of Ar1 to Ar3 includes an amino group as a substituent.

[0149] In some embodiments, the compound represented by the chemical formula HT may be a carbazole compound containing a substituted or unsubstituted carbazole group in at least one of Ar1 and Ar2, or a fluorene compound containing a substituted or unsubstituted fluorene group in at least one of Ar1 and Ar2.

[0150] Non-limiting examples of compounds represented by the chemical formula HT are as follows.

[0151]

[0152]

[0153]

[0154]

[0155]

[0156]

[0157] For example, hole transport region 120 may include m-MTDATA (4,4',4''-[tris(3-methylphenyl)phenylamino]triphenylamine), TDATA (4,4',4''-tris(N,N-diphenylamino)triphenylamine), 2-TNATA (4,4',4''-tris[N-(2-naphthyl)-N-phenylamino]triphenylamine), NPB (N,N'-di(naphthyl-1-yl)-N,N'-diphenyl-benzidine), TPD (N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1'-biphenyl]-4,4'-diamine), spiro-TPD, spiro-NPB, DNTPD (N 1 N 1 '-([1,1'-biphenyl]-4,4'-diyl)bis(N 1 -Phenyl-N 4 N 4 The following compounds are used: di-m-tolylphenyl-1,4-diamine, TAPC (4,4'-cyclohexylene-bis[N,N-bis(4-methylphenyl)aniline]), HMTPD (4,4'-bis[N,N'-(3-tolyl)amino]-3,3'-dimethylbiphenyl), TCTA (4,4',4''-tris(N-carbazolyl)triphenylamine), PANI / DBSA (polyaniline / dodecylbenzenesulfonic acid), PEDOT / PSS (poly(3,4-ethylenedioxythiophene) / poly(4-styrenesulfonate)), PANI / CSA (polyaniline / camphorsulfonic acid), PANI / PSS (polyaniline / poly(4-styrenesulfonate)), phthalocyanine compounds, carbazole compounds (N-phenylcarbazole, polyvinylcarbazole or other carbazole compounds), fluorene compounds, etc. These materials can be used alone or in combination of two or more.

[0158] The aforementioned material may be included in at least one of the hole injection layer 122, the hole transport layer 124, and the electron blocking layer 126.

[0159] The hole transport region 120 may also include a charge-generating material. Dopant materials, such as p-doped materials, can be used as charge-generating materials, thereby improving the conductivity of the hole transport region 120.

[0160] Examples of dopant materials include: metal halide compounds, such as LiF, NaCl, CsF, RbCl, RbI, CuI, and KI; quinone derivatives, such as TCNQ (tetracyanoquinone dimethane) and F4-TCNQ (2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinone dimethane); cyano-containing compounds, such as HAT-CN (dipyrazino[2,3-f:2',3'-h]quinoxaline-2,3,6,7,10,11-hexanitrile) and NDP9 (4-[[2,3-bis[cyano-(4-cyano-2,3,5,6-tetrafluorophenyl)methylene]cyclopropyl]-cyanomethyl]-2,3,5,6-tetrafluorobenzonitrile); W oxides; Mo oxides, etc. These materials can be used alone or in combination of two or more of them.

[0161] The thickness of the hole transport region 120 can be in the range of about 100 Å to about 10,000 Å (e.g., about 100 Å to about 1,500 Å).

[0162] When the hole transport region 120 includes a hole injection layer 122 and a hole transport layer 124, the thickness of the hole injection layer 122 can be in the range of about 100 Å to about 9,000 Å, about 100 Å to about 3,000 Å, or about 100 Å to about 1,000 Å. The thickness of the hole transport layer 124 can be in the range of about 50 Å to about 2,000 Å, about 100 Å to about 1,500 Å, about 100 Å to about 1,000 Å, or about 100 Å to about 600 Å.

[0163] Within the aforementioned thickness range, hole transport properties can be enhanced even under low-voltage operation, and device lifetime can be further improved.

[0164] Each layer of the hole transport region 120 can be formed by processes such as vacuum deposition, spin coating, inkjet printing, laser printing, casting, laser thermal transfer, or other processes that support the formation of the layer.

[0165] Figure 5 This is a schematic cross-sectional view showing a light-emitting device according to an embodiment.

[0166] Reference Figure 5 The first cover layer 160a may be formed on the outer surface of the first electrode 110. In some embodiments, the second cover layer 160b may be formed on the outer surface of the second electrode 150.

[0167] The refractive index of the first capping layer 160a and / or the second capping layer 160b may be about 1.6 or greater. For example, for light with a wavelength range of 550 nm to 660 nm, the refractive index of the first capping layer 160a and / or the second capping layer 160b may be about 1.6 or greater.

[0168] The first capping layer 160a and the second capping layer 160b can both be formed as an organic capping layer including organic materials, an inorganic capping layer including inorganic materials, or an organic-inorganic mixed capping layer including both organic and inorganic materials.

[0169] In some embodiments, the first capping layer 160a and / or the second capping layer 160b may include carbocyclic compounds, heterocyclic compounds, amine-containing compounds, phosphine derivatives, phthalocyanine derivatives, naphthylphthalocyanine derivatives, alkali metal complexes, alkaline earth metal complexes, etc. These materials may be used alone or in combination of two or more of them.

[0170] In an embodiment, the first capping layer 160a and / or the second capping layer 160b may include an amine-containing compound.

[0171] The aforementioned light-emitting device 100 can be applied to a display device or an electronic device, and can be configured as a light-emitting part or light-emitting unit of a display device or an electronic device.

[0172] Display devices or electronic devices may include billboards, signage displays, light sources / lighting devices, personal computers (such as laptops or desktops), mobile phones, e-books, electronic dictionaries, electronic notebooks, various sensors, diagnostic devices, and various display units in transportation vehicles (cars, airplanes, ships, trains, etc.).

[0173] In an example embodiment, the light-emitting device 100 can be applied to an organic light-emitting diode (OLED) display device or a quantum dot (QD)-OLED display device.

[0174] Figure 6 This is a schematic plan view illustrating a display device according to an embodiment.

[0175] Reference Figure 6 The display device 200 may include a display area DA and a non-display area NDA.

[0176] For example, pixel P can be set in the display area DA, and pixel P can also be not set in the non-display area NDA.

[0177] Pixel P may include at least one light-emitting device 100 as described herein. For example, multiple light-emitting devices 100 may be included in one pixel P.

[0178] In some embodiments, the non-display area NDA may be positioned along the periphery of the display area DA. Although Figure 6 The diagram shows a non-display area NDA surrounding a display area DA, but the invention is not limited thereto. For example, the non-display area NDA may be omitted or may be adjacent to one side of the display area DA.

[0179] Display device 200 may include flat panel displays, curved displays, three-dimensional displays, etc.

[0180] Figure 7 This is a schematic cross-sectional view illustrating a display device according to an embodiment. For example, Figure 7 Along the thickness direction Figure 6 A cross-sectional view taken along line I-I'. Although the electron transport region 140 is... Figure 7 It is shown as a single layer, but the electron transport region 140 may have a multilayer structure as described herein.

[0181] Reference Figure 7 The display device 200 may include a circuit layer 220 disposed on a substrate 210 and light-emitting devices 100 disposed on the circuit layer 220. For example, the display device 200 may include a plurality of light-emitting devices 100.

[0182] The substrate 210 can be used as a support substrate or backplate substrate for an image display device. A glass substrate or a plastic substrate can be used as the substrate 210.

[0183] In some embodiments, the substrate 210 may include a polymer material having transparent and flexible properties. In this case, the display device 200 may be used as a transparent flexible display device. For example, the substrate 210 may include a polymer material, such as polyimide, polysiloxane, epoxy resin, acrylic resin, polyester, etc. In an embodiment, the substrate 210 may include polyimide.

[0184] In the embodiments, the surface of the substrate 210 may be pretreated by chemical treatment using chemicals (e.g., silane coupling agents), plasma treatment, ion plating, sputtering, vapor phase reaction treatment, or vacuum deposition.

[0185] Circuit layer 220 may include transistors. Circuit layer 220 may include wiring layers and insulating layers forming a thin-film transistor array (TFT array).

[0186] Figure 8 This is a schematic cross-sectional view illustrating a display device according to an embodiment. For example, Figure 8 This is a partially enlarged cross-sectional view of the display device 200 used to describe the detailed structure of the circuit layer 220.

[0187] Reference Figure 8 The circuit layer 220 may include a buffer layer 222 disposed on the top surface of the substrate 210. Moisture permeating through the substrate 210 may be blocked by the buffer layer 222, and the diffusion of impurities between the substrate 210 and the structures disposed on the substrate 210 may be blocked.

[0188] The buffer layer 222 may include, for example, silicon oxide, silicon nitride, or silicon oxynitride. These materials may be used alone or in combination. In some embodiments, the buffer layer 222 may have a stacked structure including a silicon oxide layer and a silicon nitride layer.

[0189] Active pattern 221 can be disposed on buffer layer 222. Active pattern 221 can be repeatedly formed for each pixel. Active pattern 221 can include silicon compounds such as polysilicon. p-type dopant or n-type dopant can be doped in a portion of the active pattern 221.

[0190] In some embodiments, the active pattern 221 may include an oxide semiconductor such as indium gallium zinc oxide (IGZO), zinc tin oxide (ZTO), or ITZO.

[0191] The gate insulating layer 224 may be formed on the buffer layer 222 and cover the active pattern 221. For example, the gate insulating layer 224 may include silicon oxide, silicon nitride, or silicon oxynitride, and may have a stacked structure including a silicon oxide layer and a silicon nitride layer.

[0192] The gate electrode 223 may be disposed on the gate insulating layer 224. In an embodiment, the gate electrode 223 may have a plate shape that overlaps with the region of the active pattern 221.

[0193] In an embodiment, the gate electrode 223 may include a metal, alloy thereof, or nitride thereof, such as Ag, Mg, Al, W, Cu, Ni, Cr, Mo, Ti, Pt, Ta, Nd, Sc, etc.

[0194] An interlayer insulating layer 226 covering the gate electrode 223 may be formed on the gate insulating layer 224. The interlayer insulating layer 226 may include silicon oxide, silicon nitride, and / or silicon oxynitride, and may include a stacked structure thereof.

[0195] Drain electrode 225 and source electrode 227 may be formed on interlayer insulating layer 226. Each of drain electrode 225 and source electrode 227 may penetrate interlayer insulating layer 226 and gate insulating layer 224 to contact active pattern 221.

[0196] In an embodiment, the drain electrode 225 and the source electrode 227 may include metals, alloys thereof, or nitrides thereof, such as Ag, Mg, Al, W, Cu, Ni, Cr, Mo, Ti, Pt, Ta, Nd, or Sc.

[0197] For example, a structure including an active pattern 221, a gate electrode 223, a drain electrode 225, and a source electrode 227 can be provided as a transistor.

[0198] In some embodiments, the transistor may be connected to the first electrode 110 of the light-emitting device 100.

[0199] The via insulating layer 228 can be formed on the interlayer insulating layer 226 and cover the drain electrode 225 and the source electrode 227.

[0200] The via insulating layer 228 can accommodate a via structure that electrically connects the first electrode 110 to the drain electrode 225. In some embodiments, the via insulating layer 228 can serve as a planarization layer for the circuit layer 220. The via insulating layer 228 may include organic materials such as polyimide, epoxy resin, acrylic resin, or polyester.

[0201] The aforementioned light-emitting device 100 can be disposed on the via insulating layer 228.

[0202] The first electrode 110 can be electrically connected via a via structure to either the drain electrode 225 or the source electrode 227 included in the circuit layer 220. For example... Figure 8 As shown, the first electrode 110 may contact or be connected to the drain electrode 225 to serve as a pixel electrode patterned for each light-emitting area or pixel area.

[0203] A pixel defining layer 230 may be formed on the via insulating layer 228 to define a light-emitting region or a pixel region. The blue light-emitting region, the red light-emitting region, and the green light-emitting region may be separated and defined by the pixel defining layer 230, and the light-emitting device 100 may include a blue light-emitting device, a red light-emitting device, and a green light-emitting device.

[0204] The pixel-defining layer 230 can partially cover the first electrode 110 of each light-emitting area.

[0205] like Figure 7 As shown, hole transport region 120 and electron transport region 140 can be formed together and continuously on pixel defining layer 230 and multiple first electrodes 110. Emitting layer 130 can be formed in the form of island-shaped patterns separated for each light-emitting region or pixel region, and can be defined by pixel defining layer 230.

[0206] In some embodiments, the emitting layer 130 may also be formed continuously and in common across multiple light-emitting regions or pixel regions. In some embodiments, the hole transport region 120, the emitting layer 130, and the electron transport region 140 may all be formed separately and selectively for each light-emitting region or pixel region.

[0207] The second electrode 150 can be used as a common electrode that is continuously formed over multiple light-emitting areas or pixel areas.

[0208] The encapsulation layer 240 can be disposed on the pixel defining layer 230 and the light-emitting device 100 to protect the light-emitting device 100 from moisture or oxygen. The encapsulation layer 240 can be formed as a single-layer or multi-layer thin-film encapsulation (TFE).

[0209] Encapsulation layer 240 may include: an inorganic layer, including silicon nitride (SiN) x ), silicon dioxide (SiO) x Indium tin oxide, indium zinc oxide, or any combination thereof; an organic layer, including polyethylene terephthalate, polyethylene naphthalate, polycarbonate, polyimide, polyethylene sulfonate, polyoxymethylene, polyarylate, hexamethyldisiloxane, acrylic resin (e.g., polymethyl methacrylate, polyacrylic acid, etc.), epoxy resin (e.g., aliphatic glycidyl ether (AGE)), or any combination thereof; or a combination of an organic layer and an inorganic layer.

[0210] The display device 200 may also include a functional layer 250 disposed on the encapsulation layer 240. The functional layer 250 may include: a sensor layer, such as a touch sensor layer; or an optical layer, such as a polarization layer, a color conversion layer, or a color filter layer.

[0211] In an embodiment, window 260 may be disposed on functional layer 250. Window 260 may provide a substrate surface on which functional layer 250 is disposed. Window 260 may include polymeric materials such as polyimide, polysiloxane, epoxy resin, acrylic resin, or polyester, or may include a glass substrate or a metal substrate.

[0212] In some embodiments, the display device 200 may include a gate driver region. The gate driver region may be located on the lateral portion of the display device 200.

[0213] The scan lines can extend from the gate driver region, and the data and power lines can intersect the scan lines as they extend. For example, the data and power lines can extend perpendicular to the scan lines.

[0214] In this embodiment, multiple scan lines and multiple data lines may intersect each other. Each pixel or light-emitting device 100 may be connected to scan lines, data lines, and power lines.

[0215] The scan line can be electrically connected to the gate electrode 223. For example, the gate electrode 223 can protrude from or extend from the scan line. Data lines and / or power lines can be electrically connected to the source electrode 227.

[0216] In some embodiments, one end of the display device 200 may be electrically connected to a printed circuit board (PCB).

[0217] In this embodiment, the drive signal / drive voltage for the display device 200 can be supplied from the printed circuit board. The drive voltage can be transmitted to each of the light-emitting devices 100 or each of the pixels P via power lines.

[0218] In this embodiment, the printed circuit board may include a data driving circuit. Data signals can be transmitted to data lines via the data driving circuit, thus data signals can be supplied to each of the light-emitting devices 100 or each of the pixels P.

[0219] Figure 9 This is a block diagram of an electronic device according to an embodiment.

[0220] Reference Figure 9 The electronic device 10 according to the embodiment may include a display module 11, a processor 12, a memory 13 and a power module 14.

[0221] The processor 12 may include a central processing unit (CPU), an application processor (AP), a graphics processing unit (GPU), a communication processor (CP), an image signal processor (ISP), and / or a controller.

[0222] Data information used for the operation of processor 12 or display module 11 can be stored in memory 13. In an example where processor 12 executes an application stored in memory 13, image data signals and / or input control signals can be sent to display module 11, and display module 11 can process the received signals and output image information through the display screen.

[0223] The power module 14 may include a power supply module (such as a power adapter or battery device) and a power conversion module that converts the power supplied by the power supply module to generate power related to powering the operation of the electronic device 10.

[0224] At least one of the components of the electronic device 10 described herein may be included in the display device according to the above embodiments. In some aspects, some of the various modules that are functionally included in a single module may be included in the display device, and other modules may be disposed separately from the display device. For example, display module 11 may include the display device, and processor 12, memory 13, and power module 14 may be disposed in the electronic device 10 as a separate device from the display device.

[0225] Figure 10 These are schematic diagrams of electronic devices according to various embodiments.

[0226] Reference Figure 10 Non-limiting examples of various electronic devices employing the display device according to the above embodiments include: electronic devices for displaying images, such as smartphones 10_1a, tablet PCs 10_1b, laptop computers 10_1c, TVs 10_1d, and desktop monitors 10_1e; wearable electronic devices including a display module, such as smart glasses 10_2a, head-mounted displays 10_2b, and smartwatches 10_2c; and vehicle electronic devices 10_3 including a display module, such as central information displays (CIDs) or interior mirror displays disposed in a vehicle instrument cluster, central dashboard, dashboard, or other part of the vehicle. The electronic devices may include virtual reality glasses or augmented reality glasses.

[0227] Experimental examples, including exemplary and comparative examples, are provided below to enhance understanding of this disclosure; however, these are provided as non-limiting examples and should not be construed as limiting the scope of the appended claims. It will be apparent to those skilled in the art that various changes and modifications can be made to the disclosed examples within the scope of this disclosure and the technical concept.

[0228] The embodiments supported by this disclosure support the use of at least referenced Figure 7 , Figure 8 The methods and processes for manufacturing light-emitting devices and display devices described herein, including examples and experimental examples, are supported by the descriptions of elements (e.g., layers, emitting layers, electron transport layers, electrodes, or other layers or components) that can be "set" or "formed" according to the examples described herein, as well as the methods, processes, and techniques for setting up elements, forming elements, etc.

[0229] Example 1 An ITO substrate (Corning Corporation) with a thickness of 150 nm, serving as the anode (first electrode), was ultrasonically cleaned for 5 minutes each with isopropanol and pure water, irradiated with ultraviolet light, and exposed to ozone for 30 minutes. The substrate was then mounted in an inkjet printing apparatus.

[0230] 2-TNATA (4,4',4''-tris[N-(2-naphthyl)-N-phenylamino]triphenylamine) was inkjet printed on the anode to form a hole injection layer with a thickness of 60 nm.

[0231] A hole transport layer with a thickness of 30 nm was formed by inkjet printing TFB (poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(4,4'-(N-(4-sec-butylphenyl))diphenylamine)]) as the hole transport material onto the hole injection layer.

[0232] An emitter layer with a thickness of 25 nm was formed by inkjet printing quantum dots with an average particle size (D50) of 10 nm onto the hole transport layer.

[0233] Quantum dots are made using particles that include a ZnSeTe core, a ZnSe and ZnS shell set on the core, and oleic acid ligands bound to the surface of the shell.

[0234] ZnMgO particles with a D50 of 8 nm are inkjet printed on the emitter layer as the first particles to form a first electron transport layer with a thickness of 15 nm.

[0235] ZnMgO particles with a D50 of 3 nm are inkjet printed on the first electron transport layer as the second particles to form a second electron transport layer with a thickness of 25 nm.

[0236] LiF was inkjet printed on the second electron transport layer to form an electron injection layer with a thickness of 1 nm.

[0237] Al is inkjet printed on the electron injection layer to form a cathode (second electrode) with a thickness of 100 nm, thereby obtaining a light-emitting device.

[0238] Example 2 The light-emitting device is fabricated by the same method as in Example 1, except that inkjet printing of ZnMgO particles with a D50 of 8 nm on the second electron transport layer to form a third electron transport layer with a thickness of 10 nm and forming an electron injection layer and a cathode on the third electron transport layer.

[0239] Examples 3 to 20 Except for the changes in D50 of the quantum dot, the first particle, the second particle, and the third particle as shown in Table 1 below, the light-emitting device is manufactured using the same method as in Example 2.

[0240] Comparison Example 1 The light-emitting device is fabricated by the same method as in Example 1, except that inkjet printing ZnMgO particles with a D50 of 3 nm onto the emitting layer to form a single electron transport layer with a thickness of 40 nm to replace the first and second electron transport layers.

[0241] Comparison Example 2 The light-emitting device is fabricated by the same method as in Example 1, except that inkjet printing ZnMgO particles with a D50 of 8 nm onto the emitting layer to form a single electron transport layer with a thickness of 40 nm to replace the first and second electron transport layers.

[0242] Compare Example 3 The light-emitting device is fabricated using the same method as in Example 1, except that the D50 of the ZnMgO particles included in the first electron transport layer is changed to 3 nm and the D50 of the ZnMgO particles included in the second electron transport layer is changed to 8 nm.

[0243] Experimental Example (1) Measurement of average particle size (D50) The light-emitting devices of the above examples and comparative examples were disassembled, and the D50 of the particles included in each layer was measured using a particle size analyzer (PSA) (Mastersizer3000, Malvern Panalytic Co., Ltd.).

[0244] (2) Evaluation of luminous efficiency The measured current density for each light-emitting device in the above examples and comparative examples was 50 mA / cm². 2 The luminous efficiency was evaluated using a voltmeter (Kethley SMU 236) and a luminance meter (PR650).

[0245] The following uses the ratio of the luminous efficiency of the example and comparative example to the luminous efficiency of comparative example 1 to evaluate the luminous efficiency.

[0246] ◎: The ratio of luminous efficiency to that of Comparative Example 1 exceeds 1.15.

[0247] O: The ratio of luminous efficiency to luminous efficiency of Comparative Example 1 is in the range of 1.1 to 1.15.

[0248] △: The ratio of luminous efficiency to luminous efficiency of Comparative Example 1 is greater than or equal to 1.05 and less than 1.1.

[0249] X: The ratio of luminous efficiency to luminous efficiency of Comparative Example 1 is 1.0 or less.

[0250] (3) Evaluation of lifespan properties For each light-emitting device in the above examples and comparative examples, measurements were taken at 100 mA / cm². 2 The luminance half-life at a given current density. The luminance half-life is defined as the time until the luminance becomes half of its initial luminance.

[0251] The luminance half-life was measured using a current voltmeter (Kethley SMU 236) and a luminance meter (PR650).

[0252] The following uses the ratio of the luminance half-life of the example and comparative example to the luminance half-life of comparative example 1 to evaluate lifetime properties.

[0253] ◎: The ratio of the luminance half-life to the luminance half-life of Comparative Example 1 exceeds 1.2.

[0254] O: The ratio of the luminance half-life to the luminance half-life of Comparative Example 1 is in the range of 1.1 to 1.2.

[0255] △: The ratio of the luminance half-life to the luminance half-life of Comparative Example 1 is greater than or equal to 1.05 and less than 1.1.

[0256] X: The ratio of the luminance half-life to the luminance half-life of Comparative Example 1 is 1.0 or less.

[0257] The measurement and evaluation results are shown in Table 1 below.

[0258] In Comparative Example 1 and Comparative Example 2, “monolayer (D50: x nm)” refers to a monolayer electron transport layer using ZnMgO particles with a D50 of x nm.

[0259] [Table 1]

[0260] In an example where multiple electron transport layers are included on the emitter layer and particles with relatively large D50 are included in the electron transport layer adjacent to the emitter layer, the luminous efficiency and lifetime properties are improved compared to the comparative example.

[0261] In Example 6, where the D50 of the first particle is less than 5 nm, the lifetime properties are relatively reduced compared to those of the other examples.

[0262] In Example 7, where the D50 of the first particle is greater than 20 nm, the lifetime properties are relatively reduced compared to those of the other examples.

[0263] In Example 10, where the D50 of the second particle is less than 2 nm, the luminous efficiency and lifetime properties are relatively reduced compared to those of the other examples.

[0264] In Example 11, where the D50 of the second particle is greater than 4 nm, the luminous efficiency is relatively lower compared to that of the other examples.

[0265] In Example 15, where the D50 of the third particle is less than 5 nm, the luminous efficiency is relatively lower compared to that of the other examples.

[0266] In Example 16, where the D50 of the third particle exceeds 20 nm, the luminous efficiency is relatively lower compared to that of the other examples.

[0267] In Example 19, where the quantum dot's D50 is less than 5 nm, the lifetime properties are relatively reduced compared to other examples.

[0268] In Example 20, where the quantum dot D50 exceeds 15 nm, the lifetime properties are relatively reduced compared to other examples.

Claims

1. A light-emitting device, the light-emitting device comprising: First electrode; Second electrode; An emission layer is located between the first electrode and the second electrode; as well as An electron transport region is located between the emitter layer and the second electrode, wherein the electron transport region comprises: a first electron transport layer on the emitter layer, the first electron transport layer comprising a first particle; and a second electron transport layer on the first electron transport layer, the second electron transport layer comprising a second particle having an average particle size smaller than that of the first particle.

2. The light-emitting device according to claim 1, wherein, The average particle size of the first particle is in the range of 5 nm to 20 nm.

3. The light-emitting device according to claim 1, wherein, The average particle size of the second particle is in the range of 2 nm to 4 nm.

4. The light-emitting device according to claim 1, wherein: The electron transport region further includes a third electron transport layer on top of the second electron transport layer, and The third electron transport layer includes third particles having an average particle size larger than that of the second particles.

5. The light-emitting device according to claim 1, wherein, The emission layer comprises quantum dots.

6. The light-emitting device according to claim 5, wherein, The average particle size of the quantum dot is equal to or less than the average particle size of the first particle.

7. The light-emitting device according to claim 1, further comprising a hole transport region between the first electrode and the emitting layer, wherein, The hole transport region includes: Hole injection layer, on the first electrode; and Hole transport layer, on the hole injection layer.

8. A display device, the display device comprising: Matrix substrate; Circuit layer, on the substrate; as well as The light-emitting device is electrically connected to the circuit layer. The light-emitting device includes: a first electrode; a second electrode; an emitting layer between the first electrode and the second electrode; and an electron transport region between the emitting layer and the second electrode. The electron transport region includes: a first electron transport layer on the emitting layer, the first electron transport layer including a first particle; and a second electron transport layer on the first electron transport layer, the second electron transport layer including a second particle, the second particle having an average particle size smaller than the average particle size of the first particle.

9. The display device according to claim 8, wherein, The emitting layer includes quantum dots, and the circuit layer includes transistors connected to the first electrode of the light-emitting device.

10. An electronic device, the electronic device comprising: The display device according to claim 8; Memory; as well as A processor for executing data included in the memory that is associated with controlling the operation of the display device.

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