WO2022178702A1 - 发光器件及其制造方法、显示装置 - Google Patents

发光器件及其制造方法、显示装置 Download PDF

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WO2022178702A1
WO2022178702A1 PCT/CN2021/077611 CN2021077611W WO2022178702A1 WO 2022178702 A1 WO2022178702 A1 WO 2022178702A1 CN 2021077611 W CN2021077611 W CN 2021077611W WO 2022178702 A1 WO2022178702 A1 WO 2022178702A1
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compound
general formula
light
emitting device
atom
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PCT/CN2021/077611
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French (fr)
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孙海雁
张晓晋
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京东方科技集团股份有限公司
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Priority to PCT/CN2021/077611 priority Critical patent/WO2022178702A1/zh
Priority to US17/615,424 priority patent/US20230171983A1/en
Priority to CN202180000289.5A priority patent/CN115244726A/zh
Priority to DE112021001061.1T priority patent/DE112021001061T5/de
Publication of WO2022178702A1 publication Critical patent/WO2022178702A1/zh

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    • H10K50/11—OLEDs or polymer light-emitting diodes [PLED] characterised by the electroluminescent [EL] layers
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    • H10K50/115—OLEDs or polymer light-emitting diodes [PLED] characterised by the electroluminescent [EL] layers comprising active inorganic nanostructures, e.g. luminescent quantum dots
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    • H10K71/13—Deposition of organic active material using liquid deposition, e.g. spin coating using printing techniques, e.g. ink-jet printing or screen printing
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    • H10K85/111—Organic polymers or oligomers comprising aromatic, heteroaromatic, or aryl chains, e.g. polyaniline, polyphenylene or polyphenylene vinylene
    • H10K85/113—Heteroaromatic compounds comprising sulfur or selene, e.g. polythiophene
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    • H10K2102/101—Transparent electrodes, e.g. using graphene comprising transparent conductive oxides [TCO]
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Definitions

  • the present disclosure relates to the technical field of light-emitting diodes, and in particular, to a light-emitting device, a method for manufacturing the same, and a display device including the light-emitting device.
  • Light emitting diodes generally include structures such as anodes, cathodes, light-emitting layers, hole transport layers, and electron transport layers, and are used in various fields, such as display fields, automotive fields, and medical detection fields. According to the material type of the light-emitting layer, light-emitting diodes are generally divided into organic light-emitting diodes (Organic Light Emitting Diode, OLED) and inorganic light-emitting diodes. Inorganic light emitting diodes include, for example, quantum dot light emitting diodes (Quantum dots Light Emitting Diode, QLED).
  • Quantum dots have advantages such as high fluorescence quantum yield, narrow emission spectrum, and tunable emission spectrum, and have broad application prospects in display and other fields.
  • printing technology can be used to prepare low-cost, large-area self-luminous quantum dot light-emitting diode displays. Therefore, quantum dot light-emitting diode displays are expected to develop into one of the mainstream technologies for next-generation lighting and display applications.
  • a light emitting device including: an anode; a cathode; a light emitting layer located between the anode and the cathode; and a hole transport layer located between the anode and the light emitting layer between.
  • the hole transport layer includes a first compound and a second compound, and the absolute value of the energy level of the highest occupied molecular orbital of the second compound is greater than or equal to 5 eV and less than or equal to 6.5 eV.
  • the absolute value of the difference between the energy level of the highest occupied molecular orbital of the first compound and the energy level of the highest occupied molecular orbital of the second compound is greater than or equal to 0.2 eV.
  • the hole mobility of the second compound is greater than or equal to 10 ⁇ 4 cm 2 /Vs.
  • the molar ratio of the first compound to the second compound is 1:1 to 100:1.
  • the general formula (I) of the second compound is:
  • the relative molecular mass of the second compound is less than 4000.
  • At least one of the groups Ar 1 to Ar 3 is selected from the general formula (II) or the general formula (III).
  • X is selected from any one of O, N, S, C; a carbon atom in the general formula (II) or the X atom is connected to the N atom in the general formula (I), the general formula One carbon atom in (II) refers to one of the six carbon atoms of the two benzene rings in the general formula (II), and the six carbon atoms refer to five carbon atoms in the general formula (II)
  • the three carbon atoms of the benzene ring on the right side of the membered ring except that it is connected to the branch R 1 and the five-membered ring, and the three carbon atoms of the benzene ring on the left side of the five-membered ring are connected to the branch R 2 and the five-membered ring.
  • One carbon atom in the general formula (III) is connected to the N atom in the general formula (I), and one carbon atom in the general formula (III) refers to the three atoms in the general formula (III). Any one of the twelve remaining carbon atoms of the benzene ring other than those attached to the branched R 3 , R 4 and R 5 and the N atom.
  • the X atom in the general formula (II) is connected to the N atom in the general formula (I) through a bridge structure, and the bridge structure includes at least one benzene ring.
  • a carbon atom in the general formula (II) is directly connected to the N atom in the general formula (I) or is connected through a bridge structure, and the bridge structure includes at least one benzene ring, And/or, one carbon atom in the general formula (III) is directly connected to the N atom in the general formula (I) or connected through a bridge structure, and the bridge structure includes at least one benzene ring.
  • the remaining groups in the groups Ar 1 to Ar 3 except those selected from the general formula (II) or the general formula (III) are selected from the general formula (IV) or general formula (V).
  • One carbon atom in the general formula (V) is connected to the N atom in the general formula (I), and one carbon atom in the general formula (V) refers to the two atoms in the general formula (V). Any of the remaining nine carbon atoms of the benzene ring except the carbon atom to which the branched chain R 7 is attached and the two benzene rings are attached to each other.
  • the general formula (IV) is directly connected to the N atom in the general formula (I) or is connected through a bridge structure, the bridge structure includes at least one benzene ring, and/or, the The general formula (V) is directly connected to the N atom in the general formula (I) or is connected through a bridged structure, and the bridged structure includes at least one benzene ring.
  • each of the branches R1-R7 is selected from any of the following: substituted or unsubstituted alkyl/alkoxy groups having 1-30 carbon atoms, having 6-40 carbon atoms Atomic substituted or unsubstituted aryl/aryloxy, substituted or unsubstituted aralkyl having 7 to 40 carbon atoms.
  • the material of the first compound includes a polymer material
  • the polymer material includes polyvinylcarbazole, poly[9,9-dioctylfluorene-co-N-[4-(3- methylpropyl)]-diphenylamine], any of poly[N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)benzidine].
  • the hole transport layer has an average surface roughness of less than 5 nm.
  • the hole transport layer has an average surface roughness of less than 1 nm.
  • the light emitting device further includes an electron transport layer.
  • the material of the electron transport layer includes metal oxides.
  • the metal oxide includes at least two metals.
  • the at least two metals include Zn and at least one selected from Mg, Al, Ti, Zr, and Li, and the molar ratio of the Zn to the metal oxide is greater than or equal to 0.7 .
  • the metal oxide is Mg-doped ZnO, and the molar ratio of the Mg to the metal oxide is 0.15.
  • the electron mobility of the electron transport layer is greater than or equal to 10 ⁇ 4 cm 2 /Vs.
  • 10 ⁇ 2 ⁇ hole mobility of at least one of the first compound and the second compound the electron mobility of the electron transport layer ⁇ 102.
  • the light emitting device further includes a hole injection layer.
  • the absolute value of the difference between the energy level of the highest occupied molecular orbital of the first compound and the energy level of the highest occupied molecular orbital of the hole injection layer is less than or equal to 0.3 eV, and/or the highest occupied molecular orbital of the second compound
  • the absolute value of the difference between the energy level of the molecular orbital and the energy level of the highest occupied molecular orbital of the hole injection layer is less than or equal to 0.3 eV.
  • the material of the first compound is polyvinylcarbazole, and the molar ratio of the first compound to the second compound is 2:1.
  • the material of the hole injection layer is poly(3,4-ethylenedioxythiophene)
  • the material of the electron transport layer is ZnMgO
  • the material of the light emitting layer is CdSe quantum dots
  • the The material of the anode is indium tin oxide
  • the material of the cathode is aluminum.
  • the light-emitting layer includes quantum dots.
  • the light emitting device is a top emission type or a bottom emission type.
  • a display apparatus including the light emitting device described in any one of the preceding embodiments.
  • a method of manufacturing a light emitting device comprising: forming an anode; applying a mixed solution mixed with at least a first compound and a second compound on the anode to form a hole transport layer; A side of the hole transport layer away from the anode forms a light-emitting layer; and a side of the light-emitting layer away from the hole transport layer forms a cathode.
  • the absolute value of the energy level of the highest occupied molecular orbital of the second compound is greater than or equal to 5 eV and less than or equal to 6.5 eV.
  • the step of applying a mixed solution mixed with at least a first compound and a second compound on the anode to form a hole transport layer comprises: mixing the first compound and the second compound in a molar ratio Mixing in a ratio of 1:1 to 100:1 to obtain the mixed solution; and applying the mixed solution on the anode by coating, printing or electro-hydrodynamic jet printing to form the void hole transport layer.
  • the step of mixing the first compound and the second compound in a molar ratio of 1:1 to 100:1 to obtain the mixed solution includes: mixing polyvinylcarbazole with The first compound and the second compound are mixed in a molar ratio of 2:1 to obtain the mixed solution.
  • FIG. 1 shows a structure of a light emitting device according to an embodiment of the present disclosure
  • FIG. 2 shows a schematic diagram of the energy level structure of the light-emitting device in FIG. 1;
  • Fig. 3 shows the structural formula of general formula (I) according to an embodiment of the present disclosure
  • Figure 5A shows a (partial) structural formula of a second compound according to an embodiment of the present disclosure
  • Figure 5B shows another (partial) structural formula of a second compound according to an embodiment of the present disclosure
  • Figure 5C shows yet another (partial) structural formula of a second compound according to an embodiment of the present disclosure
  • 6A-6E show pictures of hole transport layers with different surface roughnesses according to embodiments of the present disclosure
  • FIG. 7 shows a structure of a light emitting device according to an embodiment of the present disclosure
  • FIG. 8 shows a block diagram of a display device according to an embodiment of the present disclosure.
  • FIG. 9 shows a flowchart of a method of fabricating a light emitting device according to an embodiment of the present disclosure.
  • light-emitting diodes have broad application prospects in fields such as display.
  • the injection/transport efficiency of holes is generally lower than that of electrons, resulting in an electron-hole imbalance in the device.
  • this will lead to the accumulation of carriers, thereby affecting the life of the device; on the other hand, it will also lead to the loss of luminous efficiency, thereby affecting the luminous performance of the device.
  • This seriously affects the wide application of light-emitting devices. Therefore, improving the lifetime and efficiency of light-emitting devices has become an urgent problem to be solved.
  • a light emitting device includes an anode 102, a cathode 103, a light emitting layer 104 between the anode 102 and the cathode 103, and a hole transport layer (HTL) 105 between the anode 102 and the light emitting layer 104, the empty
  • the hole transport layer 105 includes a first compound and a second compound, and the absolute value of the highest occupied molecular orbital (Highest Occupied Molecular Orbital, HOMO) energy level of the second compound is greater than or equal to 5 eV and less than or equal to 6.5 eV.
  • HOMO highest occupied molecular orbital
  • the absolute value of the HOMO energy level of the second compound is greater than or equal to 5 eV and less than or equal to 5.5 eV, for example, 5 eV, 5.1 eV, 5.2 eV, 5.3 eV, 5.4 eV, 5.5 eV. In some embodiments, the absolute value of the HOMO level of the second compound is greater than or equal to 5 eV and less than or equal to 6 eV, such as 5 eV, 5.1 eV, 5.2 eV, 5.3 eV, 5.4 eV, 5.5 eV, 5.6 eV, 5.7 eV, 5.8 eV, 5.9eV, 6eV.
  • the absolute value of the HOMO energy level of the second compound is greater than or equal to 5eV and less than or equal to 6.5eV, such as 5eV, 5.1eV, 5.2eV, 5.3eV, 5.4eV, 5.5eV, 5.6eV, 5.7eV, 5.8eV, 5.9eV, 6eV, 6.1eV, 6.2eV, 6.3eV, 6.4eV, 6.5eV.
  • the light emitting device 100 shown in FIG. 1 is an upright structure (ie, the anode 102 is below and the cathode 103 is above), this is only an example, and the light emitting device 100 may also be an inverted structure (ie Cathode 103 is below and anode 102 is above).
  • open language "A includes B and C” means that A includes at least B and C, but may also include any other suitable structure.
  • the phrase "the hole transport layer 105 includes the first compound and the second compound” means that the hole transport layer 105 includes at least the first compound and the second compound, but may also include any other suitable materials as required. The embodiment does not specifically limit this.
  • FIG. 2 shows a schematic diagram of the energy level structure of the light emitting device 100 .
  • holes are injected from anode 102, electrons are injected from cathode 103, holes are transferred to light-emitting layer 104 via hole injection layer 107 (described below) and hole transport layer 105, and electrons are transferred via the electron transport layer 106 is passed to the light emitting layer 104 .
  • the injected holes and electrons recombine and generate photons through radiative transitions, thereby realizing light emission.
  • the hole transport layer 105 By making the hole transport layer 105 include the first compound and the second compound, and by making the first compound and the second compound complex in terms of HOMO energy levels (eg, the first compound and the second compound have different HOMO energy levels), Compared with the hole transport layer in the conventional technology, the hole transport layer 105 can be made to exhibit a more excellent "energy level transition" effect, which can not only promote the injection of holes from the hole injection layer 107 to the hole transport layer 105 , thereby increasing the hole injection, improving the hole injection capability, and improving the electron-hole recombination, so that the voltage of the light-emitting device 100 can be lowered and the current efficiency can be increased; it can also promote the injection of holes from the hole transport layer 105 to the light-emitting layer 104.
  • HOMO energy levels eg, the first compound and the second compound have different HOMO energy levels
  • the material of the first compound includes a polymer material, and the polymer material includes but is not limited to polyvinyl carbazole (PVK), poly[9,9-dioctylfluorene-co-N-[4-(3- Methylpropyl)]-diphenylamine] (Poly[9,9-dioctylfluorene-co-N-[4-(3-methylpropyl)]-diphenylamine], TFB), poly[N,N′-bis(4- Butylphenyl)-N,N'-bis(phenyl)benzidine](poly[N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)benzidine], Poly-TPD) any of the.
  • the hole mobility of the first compound is in the range of 10 -6 cm 2 /Vs to 10 -2 cm 2 /Vs.
  • Figure 3 shows the general formula (I) of the second compound.
  • the groups Ar 1 to Ar 3 are all connected to the N atom.
  • the groups Ar 1 to Ar 3 represent any suitable groups that conform to the performance parameters of the second compound (such as HOMO level, hole mobility, solubility, etc.), and the groups Ar 1 to Ar 3 will be described in detail below.
  • the relative molecular mass of the second compound is less than 4000. During the preparation of the light-emitting device 100, the relative molecular mass of less than 4000 makes the second compound have better solubility in the solvent and is not easy to be precipitated from the solution.
  • the hole transport layer 105 containing the second compound finally formed has a small surface roughness (eg, less than 1 nm).
  • At least one of the groups Ar 1 to Ar 3 is selected from the general formula (II) shown in FIG. 4A or the general formula (III) shown in FIG. 4C .
  • the general formula (II) includes two benzene rings and a five-membered ring located between and connected to the two benzene rings.
  • the X atom in the five-membered ring is selected from any one of O, N, S, and C.
  • the branch R 1 is connected to the benzene ring on the right side of the five-membered ring, and the branch R 2 is connected to the benzene ring on the left side of the five-membered ring.
  • a suitable carbon atom here refers to a carbon atom in the benzene ring that can provide a chemical bond to the branched Rx .
  • the branched chain R 1 can be connected to any one of the C 11 atom, C 12 atom, C 13 atom and C 14 atom of the benzene ring on the right side of the five-membered ring (the other two The carbon atoms are saturated with the five-membered ring, and thus cannot provide a connection to the branched chain R1).
  • Figure 4B shows several examples of branched R 1 attached to different positions on the benzene ring.
  • the branched chain R 1 is connected to the C 11 atom corresponding to the benzene ring.
  • the branched chain R 1 is connected to the C 12 atom corresponding to the benzene ring.
  • the branched chain R 1 is connected to the C 13 atom corresponding to the benzene ring.
  • the branched chain R 1 is connected to the C 14 atom corresponding to the benzene ring.
  • the branched chain R 2 can be connected to any one of the C 21 atom, C 22 atom, C 23 atom, and C 24 atom of the benzene ring on the left side of the five-membered ring.
  • a carbon atom or X atom in general formula (II) is attached to the N atom in general formula (I) above.
  • One carbon atom in the general formula (II) refers to one of the six carbon atoms of the two benzene rings in the general formula (II), and the six carbon atoms refer to the five-membered ring right in the general formula (II).
  • branch R 1 is connected to C 11 atom
  • branch R 2 is connected to C 21 atom
  • Any one of the six carbon atoms or the X atom on the five-membered ring is attached to the N atom in the general formula (I) above.
  • Figure 4C shows general formula (III). Similar to the general formula (II), the branched chains R 3 , R 4 and R 5 in the general formula (III) are connected to the corresponding benzene ring. Specifically, the branched chain R 3 can be connected to any one of the C 31 atoms, C 32 atoms, C 33 atoms, C 34 atoms and C 35 atoms of the benzene ring on the upper right of the N atom in the general formula (III); branch The chain R 4 can be connected with any one of the C 41 atoms, C 42 atoms, C 43 atoms, C 44 atoms and C 45 atoms of the benzene ring on the upper left of the N atom in the general formula (III); the branched chain R 5 can be connected with Any one of C 51 atom, C 52 atom, C 53 atom, C 54 atom and C 55 atom of the benzene ring below the N atom in the general formula (III) is connected.
  • One carbon atom in the general formula (III) is connected to the N atom in the general formula (I), and one carbon atom in the general formula (III) refers to the division and branching of the three benzene rings in the general formula (III). Chains R 3 , R 4 and R 5 are attached and any of the remaining twelve carbon atoms other than the N atom attached.
  • branch R3 is connected to C31 atom
  • branched R4 is connected to C41 atom
  • branched R5 is connected to C51 atom
  • the N atoms in are connected.
  • the remaining groups in the groups Ar 1 to Ar 3 except those selected from the general formula (II) or the general formula (III) are selected from the general formula (IV) or the general formula (IV) shown in FIG. 4D .
  • 4E shows the general formula (V).
  • the remaining two groups are selected from general formula (IV) and/or shown in FIG. 4D Or the general formula (V) shown in Figure 4E; if two groups in the groups Ar 1 to Ar 3 are selected from the general formula (II) and/or the general formula (III), the remaining one group is selected from The general formula (IV) shown in FIG.
  • the branched chain R 6 may be connected to any one of C 61 atom, C 62 atom, C 63 atom, C 64 atom, C 65 atom and C 66 atom of the benzene ring. Any one of the remaining five carbon atoms of the benzene ring other than those connected to the branched chain R 6 may be connected to the N atom in the general formula (I).
  • the branched chain R 7 may be connected to any one of the C 71 atom, the C 72 atom, the C 73 atom, the C 74 atom and the C 75 atom of the benzene ring. Any one of C 81 atoms to C 85 atoms in the general formula (IV) or any one of the four carbon atoms in the C 71 atom to C 75 atoms other than those connected to the branched chain R 7 can be combined with the general formula ( The N atoms in I) are connected.
  • the X atom in the general formula (II) when at least one of the groups Ar 1 to Ar 3 is selected from the general formula (II) and the X atom in the general formula (II) is attached to the N atom in the general formula (I), especially When the X atom is an N atom, the X atom in the general formula (II) is connected to the N atom in the general formula (I) through a bridge structure, and the bridge structure includes at least one benzene ring.
  • Figure 5A shows a structural formula of the second compound.
  • the structural formula may be the complete structural formula of the second compound, or may be a part of the complete structural formula of the second compound.
  • the X atom of the general formula (II) is connected to the N atom through the bridging structure 110 shown by the dotted line, and the other two chemical bonds of the N atom are directly connected to the general formula (V), respectively.
  • the bridge structure 110 includes three benzene rings.
  • the bridged structure 110 is not limited to this, and may also include any appropriate chemical structures such as one benzene ring, two benzene rings, four or more benzene rings, a combination of benzene rings and other chemical structures, and the like.
  • the general formula (II) when at least one of the groups Ar 1 to Ar 3 is selected from the general formula (II) and the carbon atom in the general formula (II) is attached to the N atom in the general formula (I), the general formula The carbon atoms in the formula (II) and the N atoms in the general formula (I) can be directly connected, or can be connected through a bridge structure, and the bridge structure includes at least one benzene ring.
  • Figure 5B shows another structural formula of the second compound.
  • the structural formula may be the complete structural formula of the second compound, or may be a part of the complete structural formula of the second compound.
  • one carbon atom on the benzene ring of the general formula (II) is directly connected to the N atom, and the other two chemical bonds of the N atom are directly connected to the general formula (V), respectively.
  • the bridge structure when at least one of the groups Ar 1 to Ar 3 is selected from the general formula (III), one carbon atom in the general formula (III) can be directly connected to the N atom in the general formula (I) , can also be connected by a bridge structure, the bridge structure includes at least one benzene ring. In some embodiments, when at least one of the groups Ar 1 to Ar 3 is selected from the general formula (IV), one carbon atom in the general formula (IV) can be directly connected to the N atom in the general formula (I) , can also be connected by a bridge structure, the bridge structure includes at least one benzene ring.
  • one carbon atom in the general formula (V) can be directly connected to the N atom in the general formula (I) , can also be connected by a bridge structure, the bridge structure includes at least one benzene ring.
  • Figure 5C shows yet another structural formula of the second compound.
  • the structural formula may be the complete structural formula of the second compound, or may be a part of the complete structural formula of the second compound.
  • the two chemical bonds of the N atom are directly connected to the general formula (V), respectively, and the other chemical bond of the N atom is connected to the general formula (V) through the bridging structure 110 shown by the dotted line.
  • bridge structure 110 includes a benzene ring.
  • the bridged structure 110 is not limited thereto, for example, it may also include any suitable chemical structures such as two or more benzene rings, a combination of benzene rings and other chemical structures, and the like.
  • the second compound has appropriate performance parameters by selecting appropriate structural formulas (eg, general formulae (II), (III), (IV), (V)) for the groups Ar 1 to Ar 3 in general formula (I) (eg HOMO level, hole mobility, solubility, etc.).
  • the hole transport layer 105 is formed by mixing such a second compound with the above-mentioned first compound, so that the hole transport layer 105 has a sufficiently deep HOMO level, so that the hole transport layer 107 and the hole transport in the light emitting device 100 can be reduced.
  • the energy barrier between the layers 105 increases hole injection and improves the hole injection capability, thereby improving electron-hole recombination, so that the voltage of the light emitting device 100 can be lowered and the current efficiency can be increased.
  • the second compound having a sufficiently deep HOMO level can also reduce the energy barrier between the hole transport layer 105 including the second compound and the light-emitting layer 104 , thereby reducing the amount of holes in the hole transport layer 105
  • the accumulation at the interface with the light-emitting layer 104 effectively slows down the degradation process of the hole transport layer 105 , prolongs the lifespan of the light-emitting device 100 , and improves the stability of the light-emitting device 100 .
  • each of the above-mentioned branched chains R 1 to R 7 may be selected from any one of the following: substituted or unsubstituted alkyl/alkoxy groups having 1 to 30 carbon atoms, 6 Substituted or unsubstituted aryl/aryloxy groups of ⁇ 40 carbon atoms, substituted or unsubstituted aralkyl groups of 7 to 40 carbon atoms.
  • the aryl group can be, for example, any suitable chemical structure such as methyl, tert-butyl, and the like, and the aryl group can be, for example, any suitable chemical structure such as a benzene ring, biphenyl, naphthalene, and the like.
  • substituted or unsubstituted XX group indicate that the H atom on the XX group may or may not be substituted. Any suitable chemical element or group may be used to replace the H atom on the XX group, which is not limited by the embodiments of the present disclosure. For example, a halogen atom can be used to replace the H atom on the XX group.
  • H atoms on the alkyl/alkoxy group with 1-30 carbon atoms may be substituted by any other suitable element or group, or may not be substituted; Some H atoms on the aryl group/aryloxy group can be substituted by any other suitable element or group, or can not be substituted; some H atoms on the aralkyl group with 7-40 carbon atoms can be substituted by other Any appropriate element or group may be substituted or unsubstituted. Selecting such a branched structure can increase the solubility of the second compound and make it difficult to precipitate in the solution, so that the second compound and the first compound can be better mixed, so as to improve the current efficiency and lifetime of the light-emitting device 100 .
  • the absolute value of the difference between the energy level of the highest occupied molecular orbital of the first compound and the energy level of the highest occupied molecular orbital of the second compound is greater than or equal to 0.2 eV, that is,
  • such an energy level design makes an appropriate energy level difference between the first compound and the second compound, which is appropriate
  • the energy level difference between the two compounds will not reflect the energy level matching of the two compounds because the energy level difference is too small, nor will it be unfavorable for holes to be injected from the hole injection layer 107 to the hole transport layer 105 because the energy level difference is too large. .
  • Such energy level design is beneficial to improve hole injection and increase the recombination probability of electron holes.
  • the absolute value of the HOMO energy level of the first compound is in the range of 5 eV to 6 eV
  • the absolute value of the HOMO energy level of the second compound is in the range of 5 eV to 6.5 eV.
  • the hole transport layer 105 if one of the first compound and the second compound is selected to have a shallower HOMO energy level, the other is selected to have a deeper HOMO energy level, so that the first compound and the second compound are selected to have a shallower HOMO energy level. A proper HOMO level difference is always maintained between the two compounds.
  • the first compound has a shallower HOMO energy level than the second compound, eg,
  • 5.4 eV,
  • 6.0 eV.
  • the second compound has a shallower HOMO energy level than the first compound, eg,
  • 5.3 eV,
  • 5.7 eV.
  • the relationship between the HOMO energy levels of the hole injection layer 107, the hole transport layer 105, and the light-emitting layer 104 is:
  • the first compound and the second compound have Compounds with a shallower HOMO level
  • HOMO energy level difference between the first compound and the second compound, which is equivalent to "building" two gently progressive energy level transition bridges between the hole injection layer 107 and the light emitting layer 104, which is beneficial to Holes are injected from the hole injection layer 107 having a shallower HOMO energy level to the hole transport layer 105 , and then injected from the hole transport layer 105 to the light emitting layer 104 having a deeper HOMO energy level.
  • Such energy level design is beneficial to improve hole injection, thereby improving the recombination probability of electron holes, so that the voltage of the light emitting device 100 can be lowered and the current efficiency can be improved.
  • the hole mobility of the second compound is greater than or equal to 10 -4 cm 2 /Vs, such as greater than or equal to 10 -3 cm 2 /Vs, greater than or equal to 10 -2 cm 2 /Vs, greater than or equal to 10 -1 cm 2 /Vs, etc.
  • terms such as “hole mobility of XX” refer to the inherent hole mobility of XX itself, that is, its own inherent property, rather than to XX embodied in the light-emitting device 100 .
  • hole mobility usually, the light-emitting device 100 contains a plurality of film layers.
  • the hole mobility of XX in the light-emitting device 100 and its inherent hole mobility are usually There will be some differences.
  • terms such as “electron mobility of XX” refer to XX’s own intrinsic electron mobility, ie, its own intrinsic property, rather than to the electron mobility that XX exhibits in light emitting device 100 .
  • the hole transport layer 105 containing the second compound has higher hole mobility, thereby reducing the injection/transport efficiency of holes and electrons in the light-emitting device 100
  • the difference between the injection/transport efficiency of the light emitting device 100 improves the balance of electrons and holes in the light emitting device 100 , thereby improving the current efficiency and lifetime of the light emitting device 100 .
  • the molar ratio of the first compound to the second compound is 1:1 to 100:1, for example, the molar ratio of the first compound to the second compound may be 100:1, 10:1, 10:3 , 2:1, 1.5:1, 1:1 and other appropriate ratios.
  • the voltage of the light-emitting device 100 can be lowered, and the current efficiency of the light-emitting device 100 can be improved.
  • the hole transport layer 105 has an average surface roughness of less than 5 nm, eg, less than 4 nm, less than 3 nm, less than 2 nm, less than 1 nm, and the like.
  • Factors such as the doping ratio of the second compound in the first compound and the relative molecular mass of the second compound can affect the average surface roughness of the hole transport layer 105 .
  • Appropriate surface roughness of the hole transport layer 105 is beneficial to make the other one or more film layers formed thereon (eg, the light emitting layer 104, the electron transport layer 106, the cathode 103, etc.) relatively flat.
  • the appropriate surface roughness of the hole transport layer 105 does not allow it to pierce other layers formed thereon, so that problems such as short circuits or material degradation in the light emitting device do not occur, thereby improving device efficiency.
  • light emitting layer 104 may be any suitable light emitting layer.
  • Materials of the light emitting layer 104 include organic materials or inorganic materials.
  • the light emitting layer 104 is a light emitting layer formed of an organic material, so that the light emitting device 100 including the light emitting layer 104 is an organic light emitting diode (Organic Light Emitting Diode, OLED).
  • OLED Organic Light Emitting Diode
  • the light-emitting layer 104 is a light-emitting layer formed of an inorganic material, for example, the inorganic material is quantum dots, so that the light-emitting device 100 including the light-emitting layer 104 is a quantum dot light-emitting diode (Quantum dots Light Emitting Diode, QLED) .
  • Quantum dots have the advantages of high fluorescence quantum yield, narrow emission spectrum, tunable emission spectrum, etc., and have broad application prospects in display and other fields.
  • the material of the quantum dot may be any appropriate material, and the embodiment of the present disclosure does not specifically limit the material of the quantum dot.
  • the material of the quantum dots may be II-VI group compounds, perovskites, III-V group compounds, I-III-VI group compounds, IV-VI group compounds, silicon-based quantum dots, carbon quantum dots, and the like.
  • the absolute value of the HOMO energy level of the light emitting layer 104 is in the range of 5.5eV ⁇ 6.5eV.
  • the hole transport layer 105 include the first compound and the second compound, the hole injection capability can be improved, the hole mobility can be improved, the voltage of the QLED device can be reduced, and the excitons can be reduced in the hole transport.
  • the stacking of the interface between the layer 105 and the light emitting layer 104 can effectively slow down the deterioration process of the hole transport layer 105, thereby prolonging the life of the light emitting device 100 and improving its current efficiency.
  • the material of anode 102 may include any suitable material, such as a material having a high work function.
  • the material of the anode 102 includes conductive metals or oxides thereof that readily inject holes, including but not limited to indium tin oxide (ITO), indium zinc oxide (IZO), aluminum, aluminum doped zinc oxide, Gold, silver, etc.
  • ITO indium tin oxide
  • IZO indium zinc oxide
  • aluminum aluminum doped zinc oxide
  • Gold gold
  • silver etc.
  • Other suitable anode materials are also possible.
  • the material of the anode 102 can be made of transparent oxide ITO, IZO and other materials, and the film thickness can be 80-200 nm.
  • the material of the anode 102 can be a composite layer of transparent oxide, such as "Ag/ITO" or "Ag/IZO".
  • the thickness of the metal layer eg, Ag
  • the thickness of the metal oxide layer eg, ITO or IZO
  • the reference value of the average reflectance of the anode 102 in the visible light region may be, for example, 85% to 95%.
  • Cathode 103 may comprise any suitable material.
  • the material of the cathode 103 may be selected from any one of ITO, aluminum, silver, gold, etc., which is not specifically limited in this embodiment.
  • the light emitting device 100 may further include a hole injection layer (HIL) 107 located between the anode 102 and the hole transport layer 105 .
  • the hole injection layer 107 can be used to lower the hole injection barrier and improve the hole injection efficiency.
  • the hole injection layer 107 may include organic materials and/or inorganic materials.
  • the hole injection layer 107 can be formed using a material such as polystyrene sulfonate:poly(3,4-ethylenedioxythiophene) (PSS:PEDOT), NiOx , or the like, or the hole transport material can be type doping to form the hole injection layer 107 .
  • the absolute value of the difference between the energy level of the highest occupied molecular orbital of the first compound and the energy level of the highest occupied molecular orbital of the hole injection layer 107 is less than or equal to 0.3 eV, that is,
  • and/or the absolute value of the difference between the energy level of the highest occupied molecular orbital of the second compound and the energy level of the highest occupied molecular orbital of the hole injection layer 107 is less than or equal to 0.3 eV, that is,
  • the hole transport layer 105 acts as a whole film layer composed of the first compound and the second compound, and it reflects an overall HOMO energy level.
  • HOMO level refers to the HOMO level exhibited by the hole transport layer 105 as a whole.
  • the absolute value of the difference between the energy level of the highest occupied molecular orbital of the hole injection layer 107 and the energy level of the highest occupied molecular orbital of the hole transport layer 105 is less than 0.40 eV, that is, the
  • the energy level barrier between the hole injection layer 107 and the hole transport layer 105 can be lowered, and the hole injection efficiency can be improved.
  • the absolute value of the difference between the energy level of the highest occupied molecular orbital of the hole transport layer 105 and the energy level of the highest occupied molecular orbital of the light emitting layer 104 is less than 0.40 eV, ie
  • the light emitting device 100 may further include an electron transport layer 106 located between the cathode 103 and the light emitting layer 104 .
  • the material of the electron transport layer includes a metal oxide containing at least two metal materials.
  • the at least two metals include Zn and at least one selected from Mg, Al, Ti, Zr, Li, etc., and the molar ratio of Zn to metal oxide is greater than or equal to 0.7.
  • the metal oxide is Mg-doped ZnO, and the molar ratio of Mg to metal oxide is 0.15.
  • the injection/transport efficiency of electrons is usually higher than that of holes, resulting in an electron-hole imbalance in the device.
  • the energy level of the lowest unoccupied molecular orbital (LUMO) of the electron transport layer 106 also known as the Lowest Unoccupied Molecular Orbital, LUMO
  • the work function of the cathode 103 has a large difference, so that the transport of electrons can be suppressed to a certain extent, so that the electrons and holes in the light-emitting device originally in excess of electrons tend to balance gradually, thereby improving Current efficiency of light-emitting devices.
  • the electron mobility of the electron transport layer 106 is greater than or equal to 10 ⁇ 4 cm 2 /Vs, such as greater than or equal to 10 ⁇ 3 cm 2 /Vs, greater than or equal to 10 ⁇ 2 cm 2 /Vs, and the like.
  • the hole mobility of the first compound is 4.5*10 -6 cm 2 /Vs
  • the hole mobility of the second compound is 1*10 -3 cm 2 /Vs
  • the electron mobility of the electron transport layer 106 The rate is 1.6*10 -3 cm 2 /Vs.
  • the difference between the injection/transport efficiency of electrons and the injection/transport efficiency of holes can be reduced, Therefore, the recombination probability of electron holes in the light emitting device 100 can be improved.
  • the light emitting device 100 may further include a substrate 101 .
  • the substrate 101 may be rigid or flexible.
  • the substrate 101 may be a substrate of any suitable material, such as a plastic substrate, a metal substrate, a semiconductor wafer substrate, a glass substrate.
  • the substrate 101 generally has a smooth surface to facilitate the formation of subsequent film layers thereon.
  • the light emitting device 100 may further include at least one of a hole blocking layer and an electron blocking layer or any other desired film layers as required, which is not specifically limited in the embodiments of the present disclosure.
  • the hole transport layer 105 (HTL 1 for short) includes a first compound and a second compound, the material of the first compound is PVK, and the absolute value of the HOMO energy level of the second compound is 5.38 eV , the molar ratio of the first compound and the second compound is 10:1, the film thickness of the hole transport layer HTL 1 is about 35-40 nm; the material of the hole injection layer 107 is poly(3,4-ethylenedioxythiophene) ) (PEDOT), the film thickness is about 40-45 nm; the material of the light-emitting layer 104 is CdSe quantum dots emitting red light, and the film thickness is about 10-20 nm; the material of the electron transport layer 106 is ZnMgO, whose film The layer thickness is about 30-60 nm; the material of the anode 102 is ITO, and the film thickness is about 40-45 nm; the material of the cathode 103
  • the hole mobility of the first compound is 4.5*10 -6 cm 2 /Vs
  • the hole mobility of the second compound is 1*10 -3 cm 2 /Vs
  • the electrons of the electron transport layer 106 The mobility is 1.6*10 -3 cm 2 /Vs.
  • the parameters of each film layer of the light-emitting device of this example are different from those of the light-emitting device of example 1.
  • the film parameters are exactly the same.
  • the material of the first compound in HTL 2 is PVK, and the molar ratio of the first compound to the second compound is 10:3.
  • the parameters of each film layer of the light-emitting device of this example are different from those of the light-emitting device of example 1.
  • the film parameters are exactly the same.
  • the material of the first compound in HTL 3 is PVK, and the molar ratio of the first compound to the second compound is 2:1.
  • the parameters of each film layer of the light-emitting device of this example are different from those of the light-emitting device of example 1.
  • the film parameters are exactly the same.
  • the material of the first compound in HTL 4 is PVK, and the molar ratio of the first compound to the second compound is 1:1.
  • HTL comparison 1 includes only the first compound whose material is PVK, and does not include the second compound.
  • Table 1 shows the physical properties of some film layers of the light emitting devices in Examples 1 to 4 and Comparative Example 1;
  • Table 2 shows the performance parameters of the light emitting devices in Examples 1 to 4 and Comparative Example 1.
  • the absolute value of the HOMO energy level of the hole transport layer gradually decreases. That is, as the molar ratio of the second compound in the hole transport layer gradually increases, the absolute value of the HOMO energy level of the hole transport layer gradually decreases.
  • the absolute value of its HOMO level is 5.82 eV; when the second compound in the hole transport layer accounts for the highest molar ratio , namely HTL 4 , the absolute value of its HOMO level is 5.31 eV.
  • Example 4 As can be seen from Table 2, in the order from Comparative Example 1 to Example 4, the voltage of the light-emitting device gradually decreased, and by the time of Example 3, the voltage of the light-emitting device decreased to the lowest value of 2.4V, and the voltage of the light-emitting device in Example 4 was the same as that of Example 3.
  • the voltage of the light-emitting device is the same, and it is also 2.4V; according to the order from Comparative Example 1 to Example 4, the current efficiency of the light-emitting device gradually increases and then decreases, and in Example 3, the current efficiency of the light-emitting device rises to the highest value of 20.3cd/ A, and then in Example 4, the current efficiency of the light-emitting device decreased to 14.0cd/A; in the order from Comparative Example 1 to Example 4, the brightness of the light-emitting device gradually increased and then decreased, and in Example 3, the light-emitting device The brightness of the light-emitting device increased to a maximum value of 75469 cd/cm 2 , and then the brightness of the light-emitting device decreased in Example 4 to 24917 cd/cm 2 ; in the order from Comparative Example 1 to Example 4, the average surface roughness of the hole transport layer was The degree increases gradually, being the smallest in Comparative Example 1, with an average surface roughness of 0.653 nm, and the
  • 6A-6E show pictures of hole transport layers with different average surface roughnesses in Comparative Example 1, Example 1, Example 2, Example 3, and Example 4, respectively.
  • the doping ratio of the second compound was gradually increased.
  • the second compound was not doped; in Example 1, the molar ratio of the first compound to the second compound was 10:1; in Example 2, the molar ratio of the first compound to the second compound was 10 : 3; in Example 3, the molar ratio of the first compound to the second compound was 2:1; in Example 4, the molar ratio of the first compound to the second compound was 1:1.
  • the reason for the performance parameters shown in Table 2 is that due to the higher hole mobility and deeper HOMO level of the second compound, the hole injection layer decreases with the increase of the second compound doping ratio.
  • the energy barrier between 107 and the hole transport layer 105 increases hole injection and improves electron-hole recombination, so that the voltage of the light-emitting device 100 is decreased and the current efficiency is increased.
  • the molar ratio is 2:1 (ie Example 3)
  • the voltage drops to the lowest value and the current efficiency rises to the highest value.
  • the doping ratio of the second compound is too high (for example, Example 4), the current efficiency decreases.
  • the high doping ratio of the second compound will cause the average surface roughness of the hole transport layer 105 to be too large, and the voids An excessively rough surface of the hole transport layer 105 may pierce other film layers formed thereon, causing problems such as short circuit or material deterioration in the light emitting device, thereby reducing the current efficiency of the light emitting device.
  • the emission wavelength (EL) of the light-emitting devices in each example is the same, which is 622 nm. Except that the light-emitting device in Comparative Example 1 has a Full Width at Half Maxima (FWHM) of 26 nm, the FWHM of the light-emitting devices in the other examples are all 25 nm.
  • FIG. 7 shows a light-emitting device 200 comprising: an anode 202, a cathode 203, a light-emitting layer 204 between the anode 202 and the cathode 203, and an electron transport layer 206 between the cathode 203 and the light-emitting layer 204,
  • the material of the electron transport layer 206 includes a metal oxide containing at least two metals.
  • the electron transport layer 206 include a metal oxide containing at least two metals, the transport of electrons can be suppressed to a certain extent, so that the phenomenon of electron excess in the light-emitting device can be alleviated, which is beneficial to make the electrons and electrons in the light-emitting device 200 and The holes gradually tend to balance, thereby effectively improving the current efficiency of the light emitting device 200 .
  • the electron mobility of the electron transport layer 206 is greater than or equal to 10 ⁇ 4 cm 2 /Vs.
  • the at least two metals include Zn and at least one selected from the group consisting of Mg, Al, Ti, Zr, and Li, and the molar ratio of Zn to metal oxide is greater than or equal to 0.7.
  • the metal oxide is Mg-doped ZnO, and the molar ratio of Mg to metal oxide is 0.15.
  • the light emitting device 200 further includes a hole transport layer 205 located between the anode 201 and the light emitting layer 204 .
  • the hole transport layer 205 may include only the first compound as described above, such as PVK, TFB, Poly-TPD, etc., or may include both the first compound and the second compound.
  • first compound such as PVK, TFB, Poly-TPD, etc.
  • second compound for the material of the first compound and the material of the second compound, reference may be made to the foregoing description, which will not be repeated in this embodiment of the present disclosure.
  • the anode 202 , the cathode 203 and the light-emitting layer 204 may be the same as the anode 102 , the cathode 103 and the light-emitting layer 104 described above, respectively.
  • the light emitting device 200 may further include a substrate 201 and a hole injection layer 207, which may be the same as the substrate 101 and the hole injection layer 107 described above. For the sake of brevity, the embodiments of the present disclosure will not be repeated here.
  • each film layer in the light-emitting device is as follows: the material of the electron transport layer 206 (ETL 5 for short) is a metal oxide, the metal oxide is ZnO doped with Mg, and the ratio of the molar ratio of Mg to the metal oxide is 0.05 , the film thickness of the electron transport layer 206 is about 30-60 nm; the hole transport layer 205 only includes the first compound Poly-TPD, and its film thickness is about 35-40 nm; the material of the hole injection layer 207 is poly( 3,4-ethylenedioxythiophene) (PEDOT), the film thickness of which is about 40-45 nm; the material of the light-emitting layer 204 is CdSe quantum dots emitting red light, and the film thickness is about 10-20 nm; The material is ITO, and its film thickness is about 40-45 nm; the material of the cathode 203 is Al, and its film thickness is about 100 nm.
  • the material of the electron transport layer 206 is a metal oxide
  • Example 6 the parameters of each film of the light-emitting device in this example are exactly the same as those of the light-emitting device in Example 5, except that the doping ratio of Mg in the electron transport layer (ETL 6 for short) is different.
  • the material of ETL 6 is Mg-doped ZnO, and the molar ratio of Mg to metal oxide is 0.10.
  • Example 7 the parameters of each film of the light-emitting device of this example are identical to those of the light-emitting device of Example 5, except that the doping ratio of Mg in the electron transport layer (ETL 7 for short) is different.
  • the material of ETL 7 is Mg-doped ZnO, and the molar ratio of Mg to metal oxide is 0.15.
  • Example 8 the parameters of each film of the light-emitting device in this example are exactly the same as those of the light-emitting device in Example 5, except that the doping ratio of Mg in the electron transport layer (ETL 8 for short) is different.
  • the material of ETL 8 is Mg-doped ZnO, and the molar ratio of Mg to metal oxide is 0.20.
  • ETL comparison 2 includes only ZnO without Mg doping.
  • Table 3 below shows the performance parameters of the light emitting devices in Examples 5 to 8 and Comparative Example 2.
  • the absolute value of the LUMO level of the electron transport layer gradually decreases. That is, as the molar ratio of Mg in the metal oxide gradually increases, the absolute value of the LUMO level of the electron transport layer gradually decreases, thus resulting in a difference between the LUMO level of the electron transport layer and the work function of the cathode 203 value is getting bigger and bigger.
  • the absolute value of its LUMO energy level is 3.6 eV; The absolute value is 3.08eV.
  • the doping ratio of Mg in the electron transport layer was gradually increased, which was 0 in Comparative Example 2, 0.05 in Example 5, 0.10 in Example 6, 0.15 in Example 7, and 8 is 0.20 (molar ratio).
  • the reason for the performance parameters shown in Table 3 is that with the increase of the Mg doping ratio, the difference between the LUMO level of the electron transport layer and the work function of the cathode 203 becomes larger and larger, which inhibits the electron transport to a certain extent.
  • the electrons and holes in the light-emitting device which is already in excess of electrons, tend to be gradually balanced, resulting in a gradual increase in the current efficiency of the light-emitting device 200; when the ratio of the molar ratio of Mg to metal oxide is 0.15 (ie, Example 7), light emitting The current efficiency of device 200 reaches a maximum value of 40.4 cd/A.
  • the Mg doping ratio is too high (for example, Example 8)
  • the electron transport in the light-emitting device is lower than the hole transport due to excessively inhibited electron transport, resulting in carrier imbalance in the light-emitting device again.
  • the current efficiency of the light-emitting device begins to decrease.
  • the emission wavelength of the light-emitting device in Example 6 is 621 nm
  • the emission wavelength of the light-emitting device in the other examples is the same, which is 622 nm.
  • the FWHM of the light-emitting device in Comparative Example 2 which is 26 nm
  • the FWHM of the light-emitting devices in the remaining examples are all 25 nm.
  • the light emitting device 200 can also have substantially the same technical effect as the light emitting device 100, therefore, for the sake of brevity The purpose of this is not repeated here.
  • FIG. 8 shows a block diagram of a display apparatus 300, which may include the light emitting device 100 or 200 described in any of the preceding embodiments.
  • the display device 300 may have substantially the same technical effects as the light emitting device 100 or 200 described in the previous embodiments, therefore, for the sake of brevity, repeated description is not repeated here.
  • FIG. 9 shows a flowchart of a method of manufacturing the light emitting device 100 described above. The manufacturing method 400 is described below with reference to FIGS. 1 and 9 .
  • Step S401 forming the anode 102
  • Step S402 applying a mixed solution mixed with at least the first compound and the second compound on the anode 102 to form the hole transport layer 105 ;
  • Step S403 forming the light-emitting layer 104 on the side of the hole transport layer 105 away from the anode 102;
  • Step S404 forming the cathode 103 on the side of the light-emitting layer 104 away from the hole transport layer 105,
  • the absolute value of the energy level of the highest occupied molecular orbital of the second compound is greater than or equal to 5 eV and less than or equal to 6.5 eV.
  • step S402 includes the following sub-steps S4021:
  • the “coating” here includes any suitable method such as spin coating, spray coating, knife coating, and the like.
  • sub-step S4021 may be: mixing the first compound formed of polyvinylcarbazole and the second compound in a molar ratio of 2:1 to obtain a mixed solution; and spin-coating the mixed solution on the A hole transport layer 105 is formed on the anode 102 .
  • a substrate 101 is first provided, which may be formed of any suitable material.
  • the substrate 101 is cleaned, and then a conductive film layer of indium tin oxide (ITO) is deposited on the substrate 101 and patterned to form the anode 102 .
  • the thickness of the film layer of the anode 102 is about 40-45 nm.
  • the cleaned substrate 101 carrying the anode 102 was subjected to ultraviolet ozone (UVO) treatment for about 15 min, and then transferred to a nitrogen-filled glove box.
  • UVO ultraviolet ozone
  • a solution of a hole injection material which is poly(3,4-ethylenedioxythiophene) (PEDOT), is spin-coated on the surface carrying the anode 102 .
  • PEDOT poly(3,4-ethylenedioxythiophene)
  • the rotation speed is about 3000 rpm, after rotating for about 40 s, baking at 130° C. for about 20 minutes, and placing it at room temperature to form a hole injection layer 107 , and the film thickness of the formed hole injection layer 107 is about 40-45 nm.
  • the film thickness of the layer 105 is about 35-40 nm.
  • the step of pre-mixing the mixed solution of the hole transport material may include: first dissolving a certain amount of the first compound PVK in a solvent to form a solution, and the solvent may be any suitable organic solvent, such as alcohols, methane, toluene, chlorobenzene, etc., and then a certain amount of the second compound is added to the solution so that the molar ratio of the first compound to the second compound is 2:1, thereby forming a mixed solution of hole transport materials.
  • the formed film of the light-emitting layer 104 The layer thickness is about 10-20 nm.
  • aluminum is vapor-deposited on the electron transport layer 106 and patterned to form the cathode 103, and the film thickness of the formed cathode 103 is about 100 nm.
  • the method 400 may have substantially the same technical effect as the light emitting device 100 described in the previous embodiments, therefore, for the sake of brevity, repeated descriptions are not repeated here.
  • the method of fabricating the light emitting device 200 is basically the same as that of fabricating the light emitting device 100 , and the method 500 of fabricating the light emitting device 200 will be described below with reference to FIG. 8 :
  • Step S501 forming the anode 202
  • Step S502 forming a light-emitting layer 204 on the anode 202;
  • Step S503 applying a metal oxide film layer containing at least two metals on the side of the light-emitting layer 204 away from the anode 202 to form an electron transport layer 206 ;
  • Step S504 forming the cathode 203 on the side of the electron transport layer 206 away from the light emitting layer 204 .
  • a substrate 101 is first provided, which may be formed of any suitable material.
  • the substrate 101 is cleaned, and then a conductive film layer of indium tin oxide (ITO) is deposited on the substrate 101 and patterned to form the anode 202 .
  • the thickness of the film layer of the anode 202 is about 40-45 nm.
  • the cleaned substrate 101 carrying the anode 202 was subjected to ultraviolet ozone (UVO) treatment for about 15 min, and then transferred to a nitrogen-filled glove box.
  • UVO ultraviolet ozone
  • a solution of a hole injection material which is poly(3,4-ethylenedioxythiophene) (PEDOT), is spin-coated on the surface carrying the anode 202 .
  • PEDOT poly(3,4-ethylenedioxythiophene)
  • the rotation speed is about 3000rpm, after rotating for about 40s, bake at 130°C for about 20min, and place it at room temperature to form a hole injection layer 207, and the film thickness of the formed hole injection layer 207 is about 40-45nm.
  • the rotation speed of the spin-coating metal oxide solution is about 3000 rpm, and after rotating for about 40 s, the electron transport layer 206 is formed by baking at 100° C. for 10 minutes.
  • the thickness of the formed electron transport layer 206 is about 30-60 nm.
  • aluminum is vapor-deposited on the electron transport layer 206 and patterned to form a cathode 203, and the film thickness of the formed cathode 203 is about 100 nm.
  • the method 500 may have substantially the same technical effect as the light emitting device 200 described in the previous embodiments, therefore, for the sake of brevity, repeated descriptions are not repeated here.
  • the methods described in the embodiments of the present disclosure are used to form a light-emitting device with an upright structure, this is only an example and not a limitation. within the scope of the present disclosure.
  • the manufacturing method of the light emitting device with the inverted structure is basically the same as the method 400 or the method 500 described above, and only needs to slightly adjust the manufacturing sequence.
  • a method for forming a light-emitting device with an inverted structure can be: providing a substrate; forming a cathode on the substrate; forming an electron transport layer on the side of the cathode away from the substrate; forming a light-emitting layer on the side of the electron transport layer away from the cathode; A hole transport layer is formed on the side of the light emitting layer away from the electron transport layer; a hole injection layer is formed on the side of the hole transport layer away from the light emitting layer; and an anode is formed on the side of the hole injection layer away from the hole transport layer.

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Abstract

本公开提供了一种发光器件及其制造方法、显示装置。该发光器件包括阳极；阴极；发光层，位于阳极与阴极之间；以及空穴传输层，位于阳极与发光层之间。空穴传输层包括第一化合物和第二化合物，第二化合物的最高占据分子轨道的能级的绝对值大于等于5eV且小于等于6.5eV。

Description

发光器件及其制造方法、显示装置 技术领域
本公开涉及发光二极管技术领域，尤其涉及一种发光器件及其制造方法、以及包括该发光器件的显示装置。
背景技术
发光二极管通常包括阳极、阴极、发光层、空穴传输层以及电子传输层等结构，并且被应用在各种各样的领域，诸如显示领域、汽车领域、医学检测领域等。根据发光层的材料类型，发光二极管通常分为有机发光二极管(Organic Light Emitting Diode，OLED)和无机发光二极管。无机发光二极管例如包括量子点发光二极管(Quantum dots Light Emitting Diode，QLED)。量子点具有诸如高荧光量子产率、窄发光光谱、可调节的发光光谱等优点，在显示等领域具有广阔的应用前景。尤其是，可以采用印刷技术来制备低成本、大面积的自发光型量子点发光二极管显示屏。因此，量子点发光二极管显示屏有望发展成为新一代照明和显示应用的主流技术之一。
发明内容
根据本公开的一方面，提供了一种发光器件，包括：阳极；阴极；发光层，位于所述阳极与所述阴极之间；以及空穴传输层，位于所述阳极与所述发光层之间。所述空穴传输层包括第一化合物和第二化合物，所述第二化合物的最高占据分子轨道的能级的绝对值大于等于5eV且小于等于6.5eV。
在一些实施例中，所述第一化合物的最高占据分子轨道的能级与所述第二化合物的最高占据分子轨道的能级的差的绝对值大于等于0.2eV。
在一些实施例中，所述第二化合物的空穴迁移率大于等于10 -4cm 2/Vs。
在一些实施例中，所述第一化合物与所述第二化合物的摩尔比为1∶1～100∶1。
在一些实施例中，所述第二化合物的通式(I)为：
Figure PCTCN2021077611-appb-000001
在一些实施例中，所述第二化合物的相对分子质量小于4000。
在一些实施例中，在所述通式(I)中，基团Ar 1～Ar 3中的至少一个选自通式(II)或通式(III)。
所述通式(II)为：
Figure PCTCN2021077611-appb-000002
X选自O、N、S、C中的任意一个；所述通式(II)中的一个碳原子或者所述X原子与所述通式(I)中的N原子相连，所述通式(II)中的一个碳原子是指所述通式(II)中的两个苯环的六个碳原子中的一个，所述六个碳原子是指所述通式(II)中的五元环右侧的苯环的除与支链R 1和所述五元环相连以外的三个碳原子以及所述五元环左侧的苯环的除与支链R 2和所述五元环相连以外的三个碳原子。
所述通式(III)为：
Figure PCTCN2021077611-appb-000003
所述通式(III)中的一个碳原子与所述通式(I)中的N原子相连，所述通式(III)中的一个碳原子是指所述通式(III)中的三个苯环的除与支链R 3、R 4和R 5以及N原子相连以外的其余十二个碳原子中的任意一个。
在一些实施例中，所述通式(II)中的X原子通过桥连结构与所述通式(I)中的N原子相连，所述桥连结构包括至少一个苯环。
在一些实施例中，所述通式(II)中的一个碳原子与所述通式(I) 中的N原子直接相连或通过桥连结构相连，所述桥连结构包括至少一个苯环，和/或，所述通式(III)中的一个碳原子与所述通式(I)中的N原子直接相连或通过桥连结构相连，所述桥连结构包括至少一个苯环。
在一些实施例中，在所述通式(I)中，所述基团Ar 1～Ar 3中的除选自通式(II)或通式(III)以外的其余基团选自通式(IV)或通式(V)。
所述通式(IV)为：
Figure PCTCN2021077611-appb-000004
所述通式(IV)中的苯环的除与支链R 6相连以外的其余五个碳原子中的任意一个与所述通式(I)中的N原子相连。
所述通式(V)为：
Figure PCTCN2021077611-appb-000005
所述通式(V)中的一个碳原子与所述通式(I)中的N原子相连，所述通式(V)中的一个碳原子是指所述通式(V)中的两个苯环的除与支链R 7相连以及将所述两个苯环彼此相连的碳原子以外的其余九个碳原子中的任意一个。
在一些实施例中，所述通式(IV)与所述通式(I)中的N原子直接相连或通过桥连结构相连，所述桥连结构包括至少一个苯环，和/或，所述通式(V)与所述通式(I)中的N原子直接相连或通过桥连结构相连，所述桥连结构包括至少一个苯环。
在一些实施例中，支链R1～R7中的每一个选自以下中的任意一项：具有1～30个碳原子的取代或未取代的烷基/烷氧基、具有6～40个碳原子的取代或未取代的芳基/芳氧基、具有7～40个碳原子的取代或未取代的芳烷基。
在一些实施例中，所述第一化合物的材料包括聚合物材料，所述聚合物材料包括聚乙烯咔唑、聚[9，9-二辛基芴-co-N-[4-(3-甲基丙基)]-二苯胺]、聚[N，N′-双(4-丁基苯基)-N，N′-双(苯基)联苯胺]中的任一种。
在一些实施例中，所述空穴传输层的平均表面粗糙度小于5nm。
在一些实施例中，所述空穴传输层的平均表面粗糙度小于1nm。
在一些实施例中，所述发光器件还包括电子传输层。所述电子传输层的材料包括金属氧化物。
在一些实施例中，所述金属氧化物包括至少两种金属。
在一些实施例中，所述至少两种金属包括Zn和选自Mg、Al、Ti、Zr、Li中的至少一种，并且所述Zn与所述金属氧化物的摩尔比的比值大于等于0.7。
在一些实施例中，所述金属氧化物为掺杂有Mg的ZnO，所述Mg与所述金属氧化物的摩尔比的比值为0.15。
在一些实施例中，所述电子传输层的电子迁移率大于等于10 -4cm 2/Vs。
在一些实施例中，10-2≤所述第一化合物和所述第二化合物中的至少一个的空穴迁移率：所述电子传输层的电子迁移率≤102。
在一些实施例中，所述发光器件还包括空穴注入层。所述第一化合物的最高占据分子轨道的能级与所述空穴注入层的最高占据分子轨道的能级的差的绝对值小于等于0.3eV，和/或，所述第二化合物的最高占据分子轨道的能级与所述空穴注入层的最高占据分子轨道的能级的差的绝对值小于等于0.3eV。
在一些实施例中，所述第一化合物的材料为聚乙烯咔唑，并且所述第一化合物与所述第二化合物的摩尔比为2∶1。
在一些实施例中，所述空穴注入层的材料为聚(3，4-乙烯二氧噻吩)，所述电子传输层的材料为ZnMgO，所述发光层的材料为CdSe量子点，所述阳极的材料为氧化铟锡，并且所述阴极的材料为铝。
在一些实施例中，所述发光层包括量子点。
在一些实施例中，所述发光器件为顶发射型或底发射型。
根据本公开的另一方面，提供了一种显示装置，其包括在前面任一个实施例中描述的发光器件。
根据本公开的又一方面，提供了一种制造发光器件的方法，包括：形成阳极；在所述阳极上施加至少混合有第一化合物和第二化合物的混合溶液以形成空穴传输层；在所述空穴传输层远离所述阳极的一侧形成发光层；以及在所述发光层远离所述空穴传输层的一侧形成阴极。 所述第二化合物的最高占据分子轨道的能级的绝对值大于等于5eV且小于等于6.5eV。
在一些实施例中，在所述阳极上施加至少混合有第一化合物和第二化合物的混合溶液以形成空穴传输层的步骤包括：将所述第一化合物与所述第二化合物以摩尔比为1∶1～100∶1的比例进行混合以得到所述混合溶液；以及利用涂覆、打印或者电流体动力喷印的方法，将所述混合溶液施加在所述阳极上以形成所述空穴传输层。
在一些实施例中，将所述第一化合物与所述第二化合物以摩尔比为1∶1～100∶1的比例进行混合以得到所述混合溶液的步骤包括：将由聚乙烯咔唑形成的第一化合物与所述第二化合物以摩尔比为2∶1的比例进行混合以得到所述混合溶液。
附图说明
为了更清楚地描述本公开实施例中的技术方案，下面将对实施例中所需要使用的附图作简单地介绍，显而易见地，下面描述中的附图仅仅是本公开的一些实施例，对于本领域普通技术人员来讲，在不付出创造性劳动的前提下，还可以根据这些附图获得其他的附图。
图1示出了根据本公开实施例的发光器件的结构；
图2示出了图1中的发光器件的能级结构的示意图；
图3示出了根据本公开实施例的通式(I)的结构式；
图4A示出了根据本公开实施例的通式(II)的结构式；
图4B示出了根据本公开实施例的通式(II)的结构式的变型；
图4C示出了根据本公开实施例的通式(III)的结构式；
图4D示出了根据本公开实施例的通式(IV)的结构式；
图4E示出了根据本公开实施例的通式(V)的结构式；
图5A示出了根据本公开实施例的第二化合物的一种(部分)结构式；
图5B示出了根据本公开实施例的第二化合物的另一种(部分)结构式；
图5C示出了根据本公开实施例的第二化合物的再一种(部分)结构式；
图6A-6E示出了根据本公开实施例的具有不同表面粗糙度的空穴 传输层的图片；
图7示出了根据本公开实施例的发光器件的结构；
图8示出了根据本公开实施例的显示装置的框图；以及
图9示出了根据本公开实施例的制造发光器件的方法的流程图。
具体实施方式
下面将结合本公开实施例中的附图，对本公开实施例中的技术方案进行清楚、完整地描述。显然，所描述的实施例仅仅是本公开一部分实施例，而不是全部的实施例。基于本公开中的实施例，本领域普通技术人员在没有做出创造性劳动前提下所获得的所有其他实施例，都属于本公开保护的范围。
如上所述，发光二极管在显示等领域具有广阔的应用前景。但是，在常规的发光器件中，空穴的注入/传输效率通常低于电子的注入/传输效率，导致器件中电子空穴的不平衡。这样一方面会导致载流子的积累，从而影响器件的寿命；另一方面也会导致发光效率的损失，进而影响器件的发光性能。这严重影响了发光器件的广发应用。因此，提高发光器件的寿命和效率成为亟待解决的问题。
鉴于此，根据本公开的一方面，提供了一种发光器件。参考图1，该发光器件100包括阳极102、阴极103、位于阳极102与阴极103之间的发光层104、以及位于阳极102与发光层104之间的空穴传输层(HTL)105，该空穴传输层105包括第一化合物和第二化合物，第二化合物的最高占据分子轨道(Highest Occupied Molecular Orbital，HOMO)的能级的绝对值大于等于5eV且小于等于6.5eV。
在一些实施例中，第二化合物的HOMO能级的绝对值大于等于5eV且小于等于5.5eV，例如为5eV，5.1eV，5.2eV，5.3eV，5.4eV，5.5eV。在一些实施例中，第二化合物的HOMO能级的绝对值大于等于5eV且小于等于6eV，例如为5eV，5.1eV，5.2eV，5.3eV，5.4eV，5.5eV，5.6eV，5.7eV，5.8eV，5.9eV，6eV。在一些实施例中，第二化合物的HOMO能级的绝对值大于等于5eV且小于等于6.5eV，例如为5eV，5.1eV，5.2eV，5.3eV，5.4eV，5.5eV，5.6eV，5.7eV，5.8eV，5.9eV，6eV，6.1eV，6.2eV，6.3eV，6.4eV，6.5eV。
需要说明的是，虽然图1中示出的发光器件100为正置结构(即 阳极102在下面，阴极103在上面)，但是这仅是一个示例，该发光器件100还可以为倒置结构(即阴极103在下面，阳极102在上面)。另外，开放性语言“A包括B和C”表示A至少包括B和C，但是还可以包括任何其他适当的结构。例如，短语“空穴传输层105包括第一化合物和第二化合物”是指空穴传输层105至少包括第一化合物和第二化合物，但是根据需要还可以包括其他任意适当的材料，本公开的实施例对此不作具体限定。
图2示出了该发光器件100的能级结构示意图。在正向偏压下，空穴从阳极102注入，电子从阴极103注入，空穴经由空穴注入层107(在下文中描述)和空穴传输层105传递到发光层104，电子经由电子传输层106传递到发光层104。在发光层104处，注入的空穴和电子发生复合并通过辐射跃迁产生光子，从而实现发光。通过使空穴传输层105包括第一化合物和第二化合物，并且通过使第一化合物与第二化合物在HOMO能级方面进行配合(例如第一化合物和第二化合物具有不同的HOMO能级)，可以使空穴传输层105相较于常规技术中的空穴传输层表现出更为优异的“能级过渡”作用，其既能够促进空穴从空穴注入层107注入到空穴传输层105，从而增加空穴注入，改善空穴注入能力，提高电子空穴复合，使得发光器件100的电压得以下降，电流效率得以升高；又能够促进空穴从空穴传输层105注入到发光层104，从而减少空穴在空穴传输层105与发光层104的界面处的堆积，进而有效减缓空穴传输层105的劣化过程，延长发光器件100的寿命，提高发光器件100的稳定性。
第一化合物的材料包括聚合物材料，该聚合物材料包括但不限于聚乙烯咔唑(polyvinyl carbazole，PVK)、聚[9，9-二辛基芴-co-N-[4-(3-甲基丙基)]-二苯胺](Poly[9，9-dioctylfluorene-co-N-[4-(3-methylpropyl)]-diphenylamine]，TFB)、聚[N，N′-双(4-丁基苯基)-N，N′-双(苯基)联苯胺](poly[N，N‘-bis(4-butylphenyl)-N，N’-bis(phenyl)benzidine]，Poly-TPD)中的任一种。在一些实施例中，第一化合物的空穴迁移率在10 -6cm 2/Vs～10 -2cm 2/Vs的范围内。
图3示出了第二化合物的通式(I)。在该通式(I)中，基团Ar 1～Ar 3均与N原子相连。基团Ar 1～Ar 3表示符合该第二化合物的性能参数(比 如HOMO能级、空穴迁移率、溶解度等)的任意适当的基团，并且将在下文中具体描述基团Ar 1～Ar 3的结构式。该第二化合物的相对分子质量小于4000。在制备发光器件100期间，低于4000的相对分子质量使得该第二化合物在溶剂中具有较优的溶解度，不易从溶液中析出。而且使得最终形成的包含该第二化合物的空穴传输层105具有较小的表面粗糙度(例如低于1nm)。
在通式(I)中，基团Ar 1～Ar 3中的至少一个选自图4A示出的通式(II)或图4C示出的通式(III)。
如图4A所示，该通式(II)包括两个苯环和位于该两个苯环之间且与该两个苯环均相连的五元环。五元环中的X原子选自O、N、S、C中的任意一个。支链R 1与五元环右侧的苯环相连，支链R 2与五元环左侧的苯环相连。虽然本领域技术人员当看到该通式(II)时能够明确知晓支链R 1和支链R 2与对应苯环的连接位置关系，不过为了使本公开内容更加清楚明确，申请人作出如下说明：支链R x(x＝1，2，3，4，5，6，7)连接到对应苯环的内部空白处(即，没有连接到对应苯环的某个特定碳原子上)表示该支链R x可以与对应苯环的任意一个适当的碳原子相连。这里的适当的碳原子是指苯环中能够提供化学键来与该支链R x相连的碳原子。以支链R 1为例，支链R 1能够与五元环右侧的苯环的C 11原子、C 12原子、C 13原子、C 14原子中的任意一个相连(该苯环的另外两个碳原子由于与五元环相连，化学键已饱和，因此不能提供与支链R 1的连接)。图4B示出了支链R 1连接到苯环的不同位置的几种示例。在通式(II-1)中，支链R 1与对应苯环的C 11原子相连。在通式(II-2)中，支链R 1与对应苯环的C 12原子相连。在通式(II-3)中，支链R 1与对应苯环的C 13原子相连。在通式(II-4)中，支链R 1与对应苯环的C 14原子相连。类似地，支链R 2能够与五元环左侧的苯环的C 21原子、C 22原子、C 23原子、C 24原子中的任意一个相连。
继续参考图4A，通式(II)中的一个碳原子或者X原子与上面通式(I)中的N原子相连。通式(II)中的一个碳原子是指通式(II)中的两个苯环的六个碳原子中的一个，该六个碳原子是指通式(II)中的五元环右侧的苯环的除与支链R 1相连和与五元环相连以外的三个碳原子以及五元环左侧的苯环的除与支链R 2相连和与五元环相连以外的三个碳原子。在一个示例中，支链R 1与C 11原子相连，支链R 2与C 21原 子相连，则C 12原子、C 13原子、C 14原子、C 22原子、C 23原子、C 24原子这六个碳原子中的任意一个或者五元环上的X原子与上面通式(I)中的N原子相连。
图4C示出了通式(III)。与通式(II)类似，通式(III)中的支链R 3、R 4和R 5与对应苯环相连。具体而言，支链R 3能够与通式(III)中N原子右上方的苯环的C 31原子、C 32原子、C 33原子、C 34原子以及C 35原子中的任意一个相连；支链R 4能够与通式(III)中N原子左上方的苯环的C 41原子、C 42原子、C 43原子、C 44原子以及C 45原子中的任意一个相连；支链R 5能够与通式(III)中N原子下方的苯环的C 51原子、C 52原子、C 53原子、C 54原子以及C 55原子中的任意一个相连。通式(III)中的一个碳原子与通式(I)中的N原子相连，该通式(III)中的一个碳原子是指通式(III)中的三个苯环的除与支链R 3、R 4和R 5相连以及与N原子相连以外的其余十二个碳原子中的任意一个。在一个示例中，支链R 3与C 31原子相连，支链R 4与C 41原子相连，支链R 5与C 51原子相连，则C 32原子、C 33原子、C 34原子、C 35原子、C 42原子、C 43原子、C 44原子、C 45原子、C 52原子、C 53原子、C 54原子、以及C 55原子共计十二个碳原子中的任意一个与通式(I)中的N原子相连。
在通式(I)中，基团Ar 1～Ar 3中的除选自通式(II)或通式(III)以外的其余基团选自图4D示出的通式(IV)或图4E示出的通式(V)。例如，如果基团Ar 1～Ar 3中的一个基团选自通式(II)或通式(III)，则剩余的两个基团选自图4D示出的通式(IV)和/或图4E示出的通式(V)；如果基团Ar 1～Ar 3中的两个基团选自通式(II)和/或通式(III)，则剩余的一个基团选自图4D示出的通式(IV)或图4E示出的通式(V)；如果基团Ar 1～Ar 3中的三个基团选自通式(II)和/或通式(III)，则没有基团选自图4D示出的通式(IV)或图4E示出的通式(V)。
参考图4D，支链R 6可以与苯环的C 61原子、C 62原子、C 63原子、C 64原子、C 65原子以及C 66原子中的任意一个相连。该苯环的除与支链R 6相连以外的其余五个碳原子中的任意一个可以与通式(I)中的N原子相连。
参考图4E，支链R 7可以与苯环的C 71原子、C 72原子、C 73原子、C 74原子以及C 75原子中的任意一个相连。该通式(IV)中的C 81原子～C 85原子中的任意一个或者C 71原子～C 75原子中除与支链R 7相连以外 的四个碳原子中的任意一个可以与通式(I)中的N原子相连。
在一些实施例中，当基团Ar 1～Ar 3中的至少一个选自通式(II)且通式(II)中的X原子与通式(I)中的N原子相连时，尤其是当X原子为N原子时，通式(II)中的X原子通过桥连结构与通式(I)中的N原子相连，该桥连结构包括至少一个苯环。例如，图5A示出了第二化合物的一种结构式。该结构式可以是第二化合物的完整结构式，也可以是第二化合物的完整结构式的一部分。在该结构式中，通式(II)的X原子通过虚线示出的桥连结构110与N原子相连，该N原子的另外两个化学键分别与通式(V)直接相连。在图5A中，桥连结构110包括三个苯环。但是，桥连结构110并不仅限于此，其还可以包括一个苯环、两个苯环、四个以上苯环、苯环与其他化学结构的组合等任意适当的化学结构。
在一些实施例中，当基团Ar 1～Ar 3中的至少一个选自通式(II)且通式(II)中的碳原子与通式(I)中的N原子相连时，该通式(II)中的碳原子与通式(I)中的N原子可以直接相连，也可以通过桥连结构相连，该桥连结构包括至少一个苯环。例如，图5B示出了第二化合物的另一种结构式。该结构式可以是第二化合物的完整结构式，也可以是第二化合物的完整结构式的一部分。在该结构式中，通式(II)中的苯环上的一个碳原子与N原子直接相连，该N原子的另外两个化学键分别与通式(V)直接相连。
在一些实施例中，当基团Ar 1～Ar 3中的至少一个选自通式(III)时，通式(III)中的一个碳原子可以与通式(I)中的N原子直接相连，也可以通过桥连结构相连，该桥连结构包括至少一个苯环。在一些实施例中，当基团Ar 1～Ar 3中的至少一个选自通式(IV)时，通式(IV)中的一个碳原子可以与通式(I)中的N原子直接相连，也可以通过桥连结构相连，该桥连结构包括至少一个苯环。在一些实施例中，当基团Ar 1～Ar 3中的至少一个选自通式(V)时，通式(V)中的一个碳原子可以与通式(I)中的N原子直接相连，也可以通过桥连结构相连，该桥连结构包括至少一个苯环。例如，图5C示出了第二化合物的又一种结构式。该结构式可以是第二化合物的完整结构式，也可以是第二化合物的完整结构式的一部分。在该结构式中，N原子的两个化学键分别与通式(V)直接相连，N原子的另一个化学键通过虚线示出的桥连结 构110与通式(V)相连。在图5C中，桥连结构110包括一个苯环。但是，桥连结构110并不仅限于此，例如其还可以包括两个或更多个苯环、苯环与其他化学结构的组合等任意适当的化学结构。
通过为通式(I)中的基团Ar 1～Ar 3选取合适的结构式(例如通式(II)、(III)、(IV)、(V))，使得第二化合物具有适当的性能参数(例如HOMO能级、空穴迁移率、溶解度等)。通过将这样的第二化合物与上述第一化合物混合形成空穴传输层105，使得空穴传输层105具有足够深的HOMO能级，从而能够减小发光器件100中空穴注入层107与空穴传输层105之间的能垒，增加空穴注入，改善空穴注入能力，从而提高电子空穴复合，使得发光器件100的电压得以下降，电流效率得以升高。而且，具有足够深的HOMO能级的第二化合物，还能够减小包括该第二化合物的空穴传输层105与发光层104之间的能量势垒，从而减少空穴在空穴传输层105与发光层104的界面处的堆积，进而有效减缓空穴传输层105的劣化过程，延长发光器件100的寿命，提高发光器件100的稳定性。
在一些实施例中，上述支链R 1～R 7中的每一个可以选自以下中的任意一项：具有1～30个碳原子的取代或未取代的烷基/烷氧基、具有6～40个碳原子的取代或未取代的芳基/芳氧基、具有7～40个碳原子的取代或未取代的芳烷基。所述芳基例如可以是甲基、叔丁基等任意合适的化学结构，所述芳基例如可以是苯环、联苯、萘等任意合适的化学结构。需要说明的是，在本说明书中，术语诸如“取代或未取代的XX基”表示XX基上的H原子可以被取代，也可以不被取代。用来取代XX基上的H原子的可以是任何适当的化学元素或基团，本公开的实施例对此不作限定。例如，卤素原子可以用来取代XX基上的H原子。也就是说，具有1～30个碳原子的烷基/烷氧基上的某些H原子可以被其他任意适当的元素或基团取代，也可以不被取代；具有6～40个碳原子的芳基/芳氧基上的某些H原子可以被其他任意适当的元素或基团取代，也可以不被取代；具有7～40个碳原子的芳烷基上的某些H原子可以被其他任意适当的元素或基团取代，也可以不被取代。选取这样的支链结构，可以增加第二化合物的溶解性，使其不易在溶液中析出，从而使第二化合物与第一化合物更好地混合，以提高发光器件100的电流效率和寿命。
在一些实施例中，第一化合物的最高占据分子轨道的能级与第二化合物的最高占据分子轨道的能级的差的绝对值大于等于0.2eV，即|HOMO 第一化合物-HOMO 第二化合物|≥0.2eV。在一个示例中，|HOMO 第一化合物-HOMO 第二化合物|≥0.2eV，例如0.25eV。在一个示例中，|HOMO 第一化合物-HOMO 第二化合物|≥0.3eV，例如0.35eV。在一个示例中，|HOMO 第一化合物-HOMO 第二化合物|≥0.4eV，例如0.45eV。在一个示例中，|HOMO 第一化合物-HOMO 第二化合物|≥0.5eV，例如0.55eV。在一个示例中，|HOMO 第一化合物-HOMO 第二化合物|≥0.6eV，例如0.65eV。在一个示例中，|HOMO 第一化合物-HOMO 第二化合物|≥0.7eV，例如0.75eV。在一个示例中，|HOMO 第一化合物-HOMO 第二化合物|≥0.8eV，例如0.85eV或0.9eV。在一个优选的实施例中，0.2eV≤|HOMO 第一化合物-HOMO 第二化合物|≤0.9eV，这样的能级设计，使得第一化合物与第二化合物之间具有适当的能级差，该适当的能级差既不会因为能级差过小而无法体现出两种化合物的能级搭配，又不会因为能级差过大而不利于空穴从空穴注入层107注入到空穴传输层105中。这样的能级设计，有利于提高空穴注入，提高电子空穴的复合几率。第一化合物的HOMO能级的绝对值在5eV～6eV的范围内，第二化合物的HOMO能级的绝对值在5eV～6.5eV的范围内。在空穴传输层105中，如果第一化合物和第二化合物中的一个被选择为具有较浅的HOMO能级，则另一个被选择为具有较深的HOMO能级，使得第一化合物和第二化合物两者之间始终保持适当的HOMO能级差。在一个示例中，第一化合物相较于第二化合物具有较浅的HOMO能级，例如，|HOMO 第一化合物|＝5.4eV，|HOMO 第二化合物|＝6.0eV。在另一个示例中，第二化合物相较于第一化合物具有较浅的HOMO能级，例如，|HOMO 第二化 合物|＝5.3eV，|HOMO 第一化合物|＝5.7eV。在发光器件100中，空穴注入层107、空穴传输层105以及发光层104的HOMO能级的关系为：|HOMO 空穴注 入层107|＜|HOMO 第一化合物和第二化合物中具有较浅HOMO能级的化合物|＜|HOMO 第一化合物和第二化 合物中具有较深HOMO能级的化合物|＜|HOMO 发光层104|。第一化合物和第二化合物两者之间具有适当的HOMO能级差，相当于在空穴注入层107与发光层104之间“搭建”了两个平缓递进的能级过渡桥梁，从而有利于空穴从具有较浅HOMO能级的空穴注入层107注入到空穴传输层105，进而从空穴传输层105注入到具有较深HOMO能级的发光层104。这样的能级设计，有利于提高空穴注入，从而提高电子空穴的复合几率，使 得发光器件100的电压得以下降，电流效率得以提升。
在一些实施例中，第二化合物的空穴迁移率大于等于10 -4cm 2/Vs，例如大于等于10 -3cm 2/Vs，大于等于10 -2cm 2/Vs，大于等于10 -1cm 2/Vs等。需要说明的是，在本说明书中，术语诸如“XX的空穴迁移率”是指XX自己固有的空穴迁移率，即其本身固有的属性，而不是指XX在发光器件100中体现出的空穴迁移率。通常，发光器件100内含有多个膜层，由于各个膜层之间以及单个膜层内其他材料的影响，XX在发光器件100中体现出的空穴迁移率与其本身固有的空穴迁移率通常会有一些差异。类似地，术语诸如“XX的电子迁移率”是指XX自己固有的电子迁移率，即其本身固有的属性，而不是指XX在发光器件100中体现出的电子迁移率。由于第二化合物具有较高的空穴迁移率，因此使得含有该第二化合物的空穴传输层105具有较高的空穴迁移率，从而减小发光器件100中空穴的注入/传输效率与电子的注入/传输效率之间的差异，提高发光器件100中电子空穴的平衡，进而提高发光器件100的电流效率和寿命。
在一些实施例中，第一化合物与第二化合物的摩尔比为1∶1～100∶1，例如，第一化合物与第二化合物的摩尔比可以为100∶1、10∶1、10∶3、2∶1、1.5∶1、1∶1等任意适当的比例。通过使第一化合物与第二化合物以适当的摩尔比进行混合，可以降低发光器件100的电压，提高发光器件100的电流效率。
在一些实施例中，空穴传输层105的平均表面粗糙度小于5nm，例如小于4nm，小于3nm，小于2nm，小于1nm等。第二化合物在第一化合物中的掺杂比例以及第二化合物本身的相对分子质量等因素可以影响空穴传输层105的平均表面粗糙度。空穴传输层105的合适表面粗糙度有利于使其上形成的其他一个或多个膜层(例如发光层104、电子传输层106、阴极103等)较为平坦。而且，空穴传输层105的合适表面粗糙度不会使其刺穿其上形成的其他膜层，从而不会出现发光器件内的短路或材料劣化等问题，从而提升器件效率。
返回继续参考图1，发光层104可以是任意适当的发光层。发光层104的材料包括有机材料或无机材料。在一个示例中，发光层104是由有机材料形成的发光层，从而使得包括该发光层104的发光器件100为有机发光二极管(Organic Light Emitting Diode，OLED)。在一个示 例中，该发光层104是由无机材料形成的发光层，例如该无机材料为量子点，使得包括该发光层104的发光器件100为量子点发光二极管(Quantum dots Light Emitting Diode，QLED)。量子点具有高荧光量子产率、窄发光光谱、可调发光光谱等优点，在显示等领域具有广阔的应用前景。量子点的材料可以是任意适当的材料，本公开的实施例对量子点的材料不作具体限定。例如，量子点的材料可以是II-VI族化合物、钙钛矿、III-V族化合物、I-III-VI族化合物、IV-VI族化合物、硅系量子点、碳量子点等。在一个示例中，发光层104的HOMO能级的绝对值在5.5eV～6.5eV的范围内。如何提高QLED的效率和寿命一直是业界不断探索和改进的方向。已知某些量子点的荧光效率已经可以达到一个较高的水准，但QLED性能的优化除了增强量子点材料的发光效率之外，还需要不断改进和优化各个功能层，以及各层之间的搭配效果。在本公开的实施例中，通过使空穴传输层105包括第一化合物和第二化合物，可以改善空穴注入能力，提高空穴迁移率，降低QLED器件电压，同时减少激子在空穴传输层105和发光层104界面的堆积，有效减缓空穴传输层105的劣化过程，从而能够延长发光器件100的寿命，提高其电流效率。
阳极102的材料可以包括任意适当的材料，例如具有高功函数的材料。在一些实施例中，阳极102的材料包括易于注入空穴的导电金属或其氧化物，包括但不限于氧化铟锡(ITO)、氧化铟锌(IZO)、铝、掺杂铝的氧化锌、金、银等。其他合适的阳极材料也是可以的。当该发光器件100为底发射结构时，阳极102的材料可以采用透明氧化物ITO、IZO等材料，膜层厚度可以在80～200nm。当该发光器件100为顶发射结构时，阳极102的材料可以采用透明氧化物的复合层，例如“Ag/ITO”或“Ag/IZO”等。在该透明氧化物的复合层中，金属层(例如Ag)的膜层厚度可以在80nm～100nm，金属氧化物层(例如ITO或IZO)的膜层厚度可以在5nm～10nm。阳极102在可见光区的平均反射率参考值例如可以为85％～95％。
阴极103可以包括任意适当的材料。在一些实施例中，阴极103的材料可以选自ITO、铝、银、金等中的任意一种，本实施例对此不作具体的限定。
继续参考图1，该发光器件100还可以包括空穴注入层(HIL)107， 该空穴注入层107位于阳极102与空穴传输层105之间。该空穴注入层107可以用来降低空穴注入势垒，提高空穴注入效率。在一些实施例中，空穴注入层107可以包括有机材料和/或无机材料。例如，可以使用聚苯乙烯磺酸盐∶聚(3，4-乙烯二氧噻吩)(PSS∶PEDOT)、NiO x等材料来形成空穴注入层107，也可以通过对空穴传输材料进行p型掺杂来形成空穴注入层107。在一些实施例中，第一化合物的最高占据分子轨道的能级与空穴注入层107的最高占据分子轨道的能级的差的绝对值小于等于0.3eV，即|HOMO 第一化合物-HOMO 空穴注入层107|≤0.3eV，和/或，第二化合物的最高占据分子轨道的能级与空穴注入层107的最高占据分子轨道的能级的差的绝对值小于等于0.3eV，即|HOMO 第二化合物-HOMO 空穴注入层107|≤0.3eV。对于空穴传输层105整体而言，其作为一个由第一化合物和第二化合物构成的整体膜层，其体现出的是一个整体的HOMO能级，以下提到的诸如“空穴传输层105的HOMO能级”指的是空穴传输层105作为整体而言体现出的HOMO能级。在一些实施例中，空穴注入层107的最高占据分子轨道的能级与空穴传输层105的最高占据分子轨道的能级的差的绝对值小于0.40eV，即|HOMO 空穴传 输层105-HOMO 空穴注入层107|＜0.40eV，优选小于0.30eV，小于0.20eV，小于等于0.11eV等。通过这样的HOMO能级设计，可以降低空穴注入层107与空穴传输层105之间的能级势垒，提高空穴注入效率。在一些实施例中，空穴传输层105的最高占据分子轨道的能级与发光层104的最高占据分子轨道的能级的差的绝对值小于0.40eV，即|HOMO 发光层 104-HOMO 空穴传输层105|＜0.40eV，优选小于0.30eV，小于0.20eV，小于0.10eV等。
继续参考图1，该发光器件100还可以包括电子传输层106，该电子传输层106位于阴极103与发光层104之间。电子传输层的材料包括至少含有两种金属材料的金属氧化物。在一些实施例中，该至少两种金属包括Zn和选自Mg、Al、Ti、Zr、Li等中的至少一种，并且Zn与金属氧化物的摩尔比的比值大于等于0.7。例如，在一个示例中，该金属氧化物为掺杂有Mg的ZnO，并且Mg与金属氧化物的摩尔比的比值为0.15。如前所述，在常规的发光器件中，电子的注入/传输效率通常高于空穴的注入/传输效率，从而导致器件中电子空穴的不平衡。而在本公开的实施例中，通过在电子传输层106的ZnO中掺杂合适比例 的Mg，可以使电子传输层106的最低未占据分子轨道(Lowest Unoccupied Molecular Orbital，LUMO)的能级(也称为导带底)与阴极103的功函数具有较大的差值，从而能够在一定程度上抑制电子的传输，使本来处于电子过剩的发光器件中电子和空穴逐渐趋于平衡，从而提高发光器件的电流效率。
在一些实施例中，电子传输层106的电子迁移率大于等于10 -4cm 2/Vs，例如大于等于10 -3cm 2/Vs，大于等于10 -2cm 2/Vs等。在一些实施例中，10 -2≤第一化合物和第二化合物中的至少一个的空穴迁移率：电子传输层106的电子迁移率≤10 2。在一个示例中，第一化合物的空穴迁移率为4.5*10 -6cm 2/Vs，第二化合物的空穴迁移率为1*10 -3cm 2/Vs，电子传输层106的电子迁移率为1.6*10 -3cm 2/Vs。通过为第一化合物、第二化合物以及电子传输层106选取合适的材料，使得他们具有合适的迁移率，从而能够减小电子的注入/传输效率与空穴的注入/传输效率之间的差异，因此能够提升发光器件100中电子空穴的复合几率。
该发光器件100还可以包括衬底101。衬底101可以是刚性或柔性的。衬底101可以是任意适当材料的衬底，例如塑料衬底、金属衬底、半导体晶片衬底、玻璃衬底。衬底101通常具有平滑的表面，以利于后续膜层在其上的形成。该发光器件100根据需要还可以包括空穴阻挡层和电子阻挡层中的至少一个或其他任意所需的膜层，本公开的实施例对此不作具体限定。
下面示出了发光器件100的几个具体的示例，来比较第一化合物与第二化合物的不同混合比例对发光器件100的性能影响。
示例1
发光器件中各膜层的参数如下：空穴传输层105(简称HTL 1)包括第一化合物和第二化合物，第一化合物的材料为PVK，第二化合物的HOMO能级的绝对值为5.38eV，第一化合物与第二化合物的摩尔比为10∶1，空穴传输层HTL 1的膜层厚度约为35～40nm；空穴注入层107的材料为聚(3，4-乙烯二氧噻吩)(PEDOT)，其膜层厚度约为40～45nm；发光层104的材料为发射红光的CdSe量子点，其膜层厚度约为10～20nm；电子传输层106的材料为ZnMgO，其膜层厚度约为30～60nm；阳极102的材料为ITO，其膜层厚度约为40～45nm；阴极103的材料 为Al，其膜层厚度约为100nm。在该示例1中，第一化合物的空穴迁移率为4.5*10 -6cm 2/Vs，第二化合物的空穴迁移率为1*10 -3cm 2/Vs，电子传输层106的电子迁移率为1.6*10 -3cm 2/Vs。
示例2
在该示例2中，除了空穴传输层(简称HTL 2)中第一化合物与第二化合物的摩尔比不同之外，该示例的发光器件的各膜层参数与示例1中的发光器件的各膜层参数完全相同。HTL 2中的第一化合物的材料为PVK，第一化合物与第二化合物的摩尔比为10∶3。
示例3
在该示例3中，除了空穴传输层(简称HTL 3)中第一化合物与第二化合物的摩尔比不同之外，该示例的发光器件的各膜层参数与示例1中的发光器件的各膜层参数完全相同。HTL 3中的第一化合物的材料为PVK，第一化合物与第二化合物的摩尔比为2∶1。
示例4
在该示例4中，除了空穴传输层(简称HTL 4)中第一化合物与第二化合物的摩尔比不同之外，该示例的发光器件的各膜层参数与示例1中的发光器件的各膜层参数完全相同。HTL 4中的第一化合物的材料为PVK，第一化合物与第二化合物的摩尔比为1∶1。
对比例1
在该对比例1中，除了空穴传输层(简称HTL 对比1)的材料不同之外，该对比例的发光器件的各膜层参数与示例1中的发光器件的各膜层参数完全相同。HTL 对比1仅包括材料为PVK的第一化合物，不包括第二化合物。
下面的表1示出了示例1～4和对比例1中的发光器件的部分膜层的物理特性；表2示出了示例1～4和对比例1中的发光器件的性能参数。
Figure PCTCN2021077611-appb-000006
表1 发光器件的部分膜层的物理特性
Figure PCTCN2021077611-appb-000007
表2 发光器件的性能参数
从表1可以看出，按照表中HTL 对比1、HTL 1、HTL 2、HTL 3、HTL 4的顺序，空穴传输层的HOMO能级的绝对值逐渐减小。也就是说，随着第二化合物在空穴传输层中所占摩尔比例逐渐增加，空穴传输层的HOMO能级的绝对值逐渐减小。例如，当空穴传输层仅包括第一化合物而不包括第二化合物时，即HTL 对比1，其HOMO能级的绝对值为5.82eV；当空穴传输层中的第二化合物所占摩尔比例最高时，即HTL 4，其HOMO能级的绝对值为5.31eV。
从表2可以看出，按照从对比例1到示例4的顺序，发光器件的电压逐渐降低，到示例3时，发光器件的电压降至最低值2.4V，示例4中发光器件电压与示例3中发光器件电压相同，也为2.4V；按照从对比例1到示例4的顺序，发光器件的电流效率逐渐升高再降低，到示例3时，发光器件的电流效率升至最高值20.3cd/A，而后在示例4中发光器件的电流效率降低，降至14.0cd/A；按照从对比例1到示例4的顺序，发光器件的亮度逐渐增大再减小，到示例3时，发光器件的亮度升至最大值75469cd/cm 2，而后在示例4中发光器件的亮度减小， 减小至24917cd/cm 2；按照从对比例1到示例4的顺序，空穴传输层的平均表面粗糙度逐渐增大，在对比例1中最小，平均表面粗糙度为0.653nm，在示例4中最大，平均表面粗糙度为1.398nm。图6A-6E分别示出了对比例1、示例1、示例2、示例3、以及示例4中的具有不同平均表面粗糙度的空穴传输层的图片。按照从对比例1到示例4的顺序，第二化合物的掺杂比例逐渐增大。在对比例1中，未掺杂第二化合物；在示例1中，第一化合物与第二化合物的摩尔比为10∶1；在示例2中，第一化合物与第二化合物的摩尔比为10∶3；在示例3中，第一化合物与第二化合物的摩尔比为2∶1；在示例4中，第一化合物与第二化合物的摩尔比为1∶1。产生表2所示的性能参数的原因为，由于第二化合物具有较高的空穴迁移率和较深的HOMO能级，随着第二化合物掺杂比例的增加，减小了空穴注入层107与空穴传输层105之间的能垒，增加了空穴注入，提高了电子空穴复合，从而使得发光器件100电压有所下降，电流效率得以升高，当第一化合物与第二化合物的摩尔比为2∶1时(即示例3)，电压降至最低值，电流效率升至最高值。当第二化合物掺杂比例过高时(例如示例4)，电流效率出现下降，这是由于第二化合物过高的掺杂比例，会使空穴传输层105的平均表面粗糙度过大，空穴传输层105的过于粗糙的表面会刺穿其上形成的其他膜层，使得发光器件内出现短路或材料劣化等问题，从而导致发光器件的电流效率有所降低。从表2可以看出，各个示例中的发光器件的发射波长(EL)均相同，均为622nm。除了对比例1中发光器件的半峰全宽(Full Width at Half Maxima，FWHM)为26nm，其余示例中的发光器件的FWHM均为25nm。
根据本公开的另一方面，提供了另一种发光器件。图7示出了发光器件200，该发光器件200包括：阳极202、阴极203、位于阳极202与阴极203之间的发光层204、以及位于阴极203与发光层204之间的电子传输层206，该电子传输层206的材料包括包含至少两种金属的金属氧化物。
通过使电子传输层206包括包含至少两种金属的金属氧化物，可以在一定程度上抑制电子的传输，使得发光器件中通常为电子过剩的现象得以缓解，从而有利于使发光器件200中电子和空穴逐渐趋于平衡，从而有效提升发光器件200的电流效率。
在一些实施例中，电子传输层206的电子迁移率大于等于10 -4cm 2/Vs。至少两种金属包括Zn和选自Mg、Al、Ti、Zr、Li中的至少一种，并且Zn与金属氧化物的摩尔比的比值大于等于0.7。在一个示例中，金属氧化物为掺杂有Mg的ZnO，并且Mg与金属氧化物的摩尔比的比值为0.15。通过在电子传输层206的ZnO中掺杂合适比例的Mg，可以使电子传输层206的LUMO能级与阴极203的功函数具有较大的差值，从而能够在一定程度上抑制电子的传输，使得电子和空穴逐渐趋于平衡，从而提高发光器件200的电流效率。
该发光器件200还包括空穴传输层205，空穴传输层205位于阳极201与发光层204之间。空穴传输层205可以仅包括如上所述的第一化合物，例如PVK、TFB、Poly-TPD等，也可以包括第一化合物和第二化合物两者。第一化合物的材料和第二化合物的材料可以参考前面的描述，本公开实施例对此不再赘述。
阳极202、阴极203和发光层204分别可以和前面描述的阳极102、阴极103和发光层104相同。该发光器件200还可以包括衬底201和空穴注入层207，它们可以和前面描述的衬底101和空穴注入层107相同。为了简约起见，本公开实施例不再赘述。
下面示出了发光器件200的几个具体示例，来比较电子传输层206中Mg的不同掺杂比例对发光器件200的性能影响。
示例5
发光器件中各膜层的参数如下：电子传输层206(简称ETL 5)的材料为金属氧化物，该金属氧化物为掺杂有Mg的ZnO，Mg与金属氧化物的摩尔比的比值为0.05，该电子传输层206的膜层厚度约为30～60nm；空穴传输层205仅包括第一化合物Poly-TPD，其膜层厚度约为35～40nm；空穴注入层207的材料为聚(3，4-乙烯二氧噻吩)(PEDOT)，其膜层厚度约为40～45nm；发光层204的材料为发射红光的CdSe量子点，其膜层厚度约为10～20nm；阳极202的材料为ITO，其膜层厚度约为40～45nm；阴极203的材料为Al，其膜层厚度约为100nm。
示例6
在该示例6中，除了电子传输层(简称ETL 6)中Mg掺杂比例不同之外，该示例的发光器件的各膜层参数与示例5中的发光器件的各 膜层参数完全相同。ETL 6的材料为掺杂有Mg的ZnO，Mg与金属氧化物的摩尔比的比值为0.10。
示例7
在该示例7中，除了电子传输层(简称ETL 7)中Mg掺杂比例不同之外，该示例的发光器件的各膜层参数与示例5中的发光器件的各膜层参数完全相同。ETL 7的材料为掺杂有Mg的ZnO，Mg与金属氧化物的摩尔比的比值为0.15。
示例8
在该示例8中，除了电子传输层(简称ETL 8)中Mg掺杂比例不同之外，该示例的发光器件的各膜层参数与示例5中的发光器件的各膜层参数完全相同。ETL 8的材料为掺杂有Mg的ZnO，Mg与金属氧化物的摩尔比的比值为0.20。
对比例2
在该对比例1中，除了电子传输层(简称ETL 对比2)的材料不同之外，该对比例2的发光器件的各膜层参数与示例5中的发光器件的各膜层参数完全相同。ETL 对比2仅包括ZnO，不掺杂Mg。
下面的表3示出了示例5～8和对比例2中的发光器件的性能参数。
Figure PCTCN2021077611-appb-000008
表3 发光器件的性能参数
参考前面示出的表1，按照表中ETL 对比2、ETL 5、ETL 6、ETL 7、ETL 8的顺序，电子传输层的LUMO能级的绝对值逐渐减小。也就是说，随着Mg在金属氧化物中所占的摩尔比例逐渐增加，电子传输层的LUMO能级的绝对值逐渐减小，因此导致电子传输层的LUMO能级与阴极203的功函数差值越来越大。例如，当电子传输层中不掺杂Mg时，即ETL 对比2，其LUMO能级的绝对值为3.6eV；当电子传输层中Mg掺杂比例最高时，即ETL 8，其LUMO能级的绝对值为3.08eV。
从表3可以看出，按照从对比例2到示例8的顺序，发光器件的 电压逐渐降低再回升，到示例6时，发光器件的电压降至最低值2.4V，示例7和示例8中发光器件电压分别为2.6V和2.5V；按照从对比例2到示例8的顺序，发光器件的电流效率逐渐升高再降低，到示例7时，发光器件的电流效率升至最高值40.4cd/A，而后在示例8中发光器件的电流效率降低，降至32.3cd/A；按照从对比例2到示例8的顺序，发光器件的亮度逐渐增大再减小，到示例7时，发光器件的亮度升至最大值6254cd/cm 2，而后在示例8中发光器件的亮度减小，减小至4957cd/cm 2。按照从对比例2到示例8的顺序，电子传输层中Mg的掺杂比例逐渐增大，对比例2中为0，示例5中为0.05，示例6中为0.10，示例7中为0.15，示例8中为0.20(摩尔比)。产生表3所示的性能参数的原因为，随着Mg掺杂比例的增加，电子传输层的LUMO能级与阴极203的功函数差值越来越大，一定程度上抑制了电子的传输，使本就处于电子过剩的发光器件中电子和空穴逐渐趋于平衡，导致发光器件200的电流效率逐渐上升；当Mg与金属氧化物的摩尔比的比值为0.15时(即示例7)，发光器件200的电流效率达到最大值40.4cd/A。但当Mg掺杂比例过高时(例如示例8)，由于过多地抑制了电子的传输，使得发光器件中的电子传输低于空穴传输，导致发光器件再一次出现载流子不平衡，从而使得发光器件的电流效率开始下降。从表3可以看出，除了示例6中的发光器件的发射波长为621nm之外，其余各个示例中的发光器件的发射波长均相同，均为622nm。除了对比例2中发光器件的FWHM为26nm之外，其余示例中的发光器件的FWHM均为25nm。
当发光器件200中的空穴传输层205包括如前面所述的第一化合物和第二化合物两者时，该发光器件200还可以具有与发光器件100基本相同的技术效果，因此，出于简洁的目的，此处不再进行重复描述。
根据本公开的再一方面，提供了一种显示装置。图8示出了显示装置300的框图，该显示装置300可以包括在前面任一个实施例中描述的发光器件100或200。
显示装置300可以与前面实施例描述的发光器件100或200具有基本相同的技术效果，因此，出于简洁的目的，此处不再进行重复描述。
根据本公开的又一方面，提供了一种制造发光器件的方法。该方法可以用来制造在前面任一个实施例中描述的发光器件100。图9示出了制造上述发光器件100的方法的流程图。下面参考图1和图9来描述该制造方法400。
步骤S401：形成阳极102；
步骤S402：在阳极102上施加至少混合有第一化合物和第二化合物的混合溶液以形成空穴传输层105；
步骤S403：在空穴传输层105远离阳极102的一侧形成发光层104；以及
步骤S404：在发光层104远离空穴传输层105的一侧形成阴极103，
其中，第二化合物的最高占据分子轨道的能级的绝对值大于等于5eV且小于等于6.5eV。
在一些实施例中，步骤S402包括以下子步骤S4021：
将第一化合物与第二化合物以摩尔比为1∶1～100∶1的比例进行混合以得到混合溶液；以及利用涂覆、打印或者电流体动力喷印的方法，将该混合溶液施加在阳极102上以形成空穴传输层105。这里的“涂覆”包括旋涂、喷涂、刮涂等任意适当的方式。
在一些实施例中，子步骤S4021可以是：将由聚乙烯咔唑形成的第一化合物与第二化合物以摩尔比为2∶1的比例进行混合以得到混合溶液；以及将该混合溶液旋涂在阳极102上以形成空穴传输层105。
下面，以前面描述的示例3中的发光器件为例，来详细描述制造发光器件100的方法。
首先提供衬底101，衬底101可以由任何适当的材料形成。对衬底101进行清洗，然后在衬底101上沉积导电膜层氧化铟锡(ITO)并对其进行图案化，以形成阳极102。阳极102的膜层厚度约为40～45nm。然后，将清洗后的载有阳极102的衬底101进行紫外臭氧(UVO)处理约15min，然后将其转移至充满氮气保护的手套箱内。在载有阳极102的表面上旋涂空穴注入材料溶液，空穴注入材料为聚(3，4-乙烯二氧噻吩)(PEDOT)。转速约为3000rpm，旋转约40s之后，在130℃下烘烤约20min，放置到室温，形成空穴注入层107，所形成的空穴注入层107的膜层厚度约为40～45nm。之后，在空穴注入层107上旋涂预混合的空穴传输材料的混合溶液，转速约为3000rpm，旋转约40s之后，在130℃下 烘烤20min，形成空穴传输层105，空穴传输层105的膜层厚度约为35～40nm。预混合空穴传输材料的混合溶液的步骤可以包括：先将一定物质的量的第一化合物PVK溶解在溶剂中以形成溶液，溶剂可以是任何适当的有机溶剂，例如醇类、甲烷、甲苯、氯苯等，然后向该溶液中添加一定物质的量的第二化合物，使得第一化合物与第二化合物的摩尔比为2∶1，从而形成空穴传输材料的混合溶液。接着，在所形成的空穴传输层107上面旋涂CdSe量子点溶液，转速约为4000rpm，旋转约40s后，在100℃下退火约10min，形成发光层104，所形成的发光层104的膜层厚度约为10～20nm。之后在发光层104上面旋涂ZnMgO溶液，转速约为3000rpm，旋转约40s后，在100℃下烘烤10min，以形成电子传输层106，所形成的电子传输层106的膜层厚度约为30～60nm。最后，在电子传输层106上蒸镀铝并对其进行图案化，以形成阴极103，所形成的阴极103的膜层厚度约为100nm。
方法400可以与前面实施例描述的发光器件100具有基本相同的技术效果，因此，出于简洁的目的，此处不再进行重复描述。
制造发光器件200的方法与制造发光器件100的基本完全相同，下面参考图8来描述制造发光器件200的方法500：
步骤S501：形成阳极202；
步骤S502：在阳极202上形成发光层204；
步骤S503：在发光层204远离阳极202的一侧施加包含至少两种金属的金属氧化物膜层，以形成电子传输层206；以及
步骤S504：在电子传输层206远离发光层204的一侧形成阴极203。
下面，以前面描述的示例7中的发光器件为例，来详细描述制造发光器件200的方法。
首先提供衬底101，衬底101可以由任何适当的材料形成。对衬底101进行清洗，然后在衬底101上沉积导电膜层氧化铟锡(ITO)并对其进行图案化，以形成阳极202。阳极202的膜层厚度约为40～45nm。然后，将清洗后的载有阳极202的衬底101进行紫外臭氧(UVO)处理约15min，然后将其转移至充满氮气保护的手套箱内。在载有阳极202的表面上旋涂空穴注入材料溶液，空穴注入材料为聚(3，4-乙烯二氧噻吩)(PEDOT)。转速约为3000rpm，旋转约40s之后，在130℃下烘烤约20min，放置到室温，形成空穴注入层207，所形成的空穴注入层207的 膜层厚度约为40～45nm。之后，在空穴注入层107上旋涂含有第一化合物Poly-TPD的空穴传输材料溶液，转速约为3000rpm，旋转约40s之后，在130℃下烘烤约20min，形成空穴传输层205，空穴传输层205的膜层厚度约为35～40nm。接着，在所形成的空穴传输层205上面旋涂CdSe量子点溶液，转速约为4000rpm，旋转约40s后，在100℃下退火10min，形成发光层204，所形成的发光层204的膜层厚度约为10～20nm。之后在发光层204上面旋涂金属氧化物溶液，该金属氧化物为掺杂有Mg的ZnO，其中Mg与金属氧化物的摩尔比的比值为0.15。旋涂金属氧化物溶液的转速约为3000rpm，旋转约40s后，在100℃下烘烤10min，以形成电子传输层206，所形成的电子传输层206的膜层厚度约为30～60nm。最后，在电子传输层206上蒸镀铝并对其图案化，以形成阴极203，所形成的阴极203的膜层厚度约为100nm。
方法500可以与前面实施例描述的发光器件200具有基本相同的技术效果，因此，出于简洁的目的，此处不再进行重复描述。
需要说明的是，虽然本公开实施例描述的方法用来形成正置结构的发光器件，但这仅仅是示例性的而不是限制性的，倒置结构的发光器件的结构及其制造方法也涵盖在本公开的保护范围之内。倒置结构的发光器件的制造方法与上面描述的方法400或方法500基本相同，只需稍微调整制造顺序。例如，形成倒置结构的发光器件的方法可以为：提供衬底；在衬底上形成阴极；在阴极远离衬底的一侧形成电子传输层；在电子传输层远离阴极的一侧形成发光层；在发光层远离电子传输层的一侧形成空穴传输层；在空穴传输层远离发光层的一侧形成空穴注入层；以及在空穴注入层远离空穴传输层的一侧形成阳极。
在本公开的描述中，术语“上”、“下”、“左”、“右”等指示的方位或位置关系为基于附图所示的方位或位置关系，仅是为了便于描述本公开而不是要求本公开必须以特定的方位构造和操作，因此不能理解为对本公开的限制。
在本说明书的描述中，参考术语“一个实施例”、“另一个实施例”等的描述意指结合该实施例描述的具体特征、结构、材料或者特点包含于本公开的至少一个实施例中。在本说明书中，对上述术语的示意性表述不必须针对的是相同的实施例或示例。而且，描述的具体特征、结构、材料或者特点可以在任一个或多个实施例或示例中以合 适的方式结合。此外，在不相互矛盾的情况下，本领域的技术人员可以将本说明书中描述的不同实施例或示例以及不同实施例或示例的特征进行结合和组合。另外，需要说明的是，本说明书中，术语“第一”、“第二”仅用于描述目的，而不能理解为指示或暗示相对重要性或者隐含指明所指示的技术特征的数量。
如本领域技术人员将理解的，尽管在附图中以特定顺序描述了本公开中方法的各个步骤，但是这并非要求或者暗示必须按照该特定顺序来执行这些步骤，除非上下文另有明确说明。附加的或可替换的，可以将多个步骤合并为一个步骤执行，以及/或者将一个步骤分解为多个步骤执行。此外，在步骤之间可以插入其他方法步骤。插入的步骤可以表示诸如本文所描述的方法的改进，或者可以与该方法无关。此外，在下一步骤开始之前，给定步骤可能尚未完全完成。
以上所述，仅为本公开的具体实施方式，但本公开的保护范围并不局限于此。任何熟悉本技术领域的技术人员在本公开揭露的技术范围内，可轻易想到变化或替换，都应涵盖在本公开的保护范围之内。因此，本公开的保护范围应以所述权利要求的保护范围为准。

Claims (30)

  1. 一种发光器件，包括：
    阳极；
    阴极；
    发光层，位于所述阳极与所述阴极之间；以及
    空穴传输层，位于所述阳极与所述发光层之间，
    其中，所述空穴传输层包括第一化合物和第二化合物，所述第二化合物的最高占据分子轨道的能级的绝对值大于等于5eV且小于等于6.5eV。
  2. 根据权利要求1所述的发光器件，其中，所述第一化合物的最高占据分子轨道的能级与所述第二化合物的最高占据分子轨道的能级的差的绝对值大于等于0.2eV。
  3. 根据权利要求2所述的发光器件，其中，所述第二化合物的空穴迁移率大于等于10 -4cm 2/Vs。
  4. 根据权利要求1所述的发光器件，其中，所述第一化合物与所述第二化合物的摩尔比为1∶1～100∶1。
  5. 根据权利要求1所述的发光器件，其中，所述第二化合物的通式(I)为：
    Figure PCTCN2021077611-appb-100001
  6. 根据权利要求5所述的发光器件，其中，所述第二化合物的相对分子质量小于4000。
  7. 根据权利要求5所述的发光器件，
    其中，在所述通式(I)中，基团Ar 1～Ar 3中的至少一个选自通式(II)或通式(III)，
    其中，所述通式(II)为：
    Figure PCTCN2021077611-appb-100002
    X选自O、N、S、C中的任意一个；所述通式(II)中的一个碳原子或者所述X原子与所述通式(I)中的N原子相连，所述通式(II)中的一个碳原子是指所述通式(II)中的两个苯环的六个碳原子中的一个，所述六个碳原子是指所述通式(II)中的五元环右侧的苯环的除与支链R 1和所述五元环相连以外的三个碳原子以及所述五元环左侧的苯环的除与支链R 2和所述五元环相连以外的三个碳原子，以及
    其中，所述通式(III)为：
    Figure PCTCN2021077611-appb-100003
    所述通式(III)中的一个碳原子与所述通式(I)中的N原子相连，所述通式(III)中的一个碳原子是指所述通式(III)中的三个苯环的除与支链R 3、R 4和R 5以及N原子相连以外的其余十二个碳原子中的任意一个。
  8. 根据权利要求7所述的发光器件，其中，所述通式(II)中的X原子通过桥连结构与所述通式(I)中的N原子相连，所述桥连结构包括至少一个苯环。
  9. 根据权利要求7所述的发光器件，其中，
    所述通式(II)中的一个碳原子与所述通式(I)中的N原子直接相连或通过桥连结构相连，所述桥连结构包括至少一个苯环，和/或
    所述通式(III)中的一个碳原子与所述通式(I)中的N原子直接相连或通过桥连结构相连，所述桥连结构包括至少一个苯环。
  10. 根据权利要求7所述的发光器件，
    其中，在所述通式(I)中，所述基团Ar 1～Ar 3中的除选自通式(II)或通式(III)以外的其余基团选自通式(IV)或通式(V)，
    其中，所述通式(IV)为：
    Figure PCTCN2021077611-appb-100004
    所述通式(IV)中的苯环的除与支链R 6相连以外的其余五个碳原子中的任意一个与所述通式(I)中的N原子相连，并且
    其中，所述通式(V)为：
    Figure PCTCN2021077611-appb-100005
    所述通式(V)中的一个碳原子与所述通式(I)中的N原子相连，所述通式(V)中的一个碳原子是指所述通式(V)中的两个苯环的除与支链R 7相连以及将所述两个苯环彼此相连的碳原子以外的其余九个碳原子中的任意一个。
  11. 根据权利要求10所述的发光器件，其中，
    所述通式(IV)与所述通式(I)中的N原子直接相连或通过桥连结构相连，所述桥连结构包括至少一个苯环，和/或
    所述通式(V)与所述通式(I)中的N原子直接相连或通过桥连结构相连，所述桥连结构包括至少一个苯环。
  12. 根据权利要求10所述的发光器件，其中，支链R 1～R 7中的每一个选自以下中的任意一项：具有1～30个碳原子的取代或未取代的烷基/烷氧基、具有6～40个碳原子的取代或未取代的芳基/芳氧基、具有7～40个碳原子的取代或未取代的芳烷基。
  13. 根据权利要求1所述的发光器件，其中，所述第一化合物的材料包括聚合物材料，所述聚合物材料包括聚乙烯咔唑、聚[9，9-二辛基芴-co-N-[4-(3-甲基丙基)]-二苯胺]、聚[N，N′-双(4-丁基苯基)-N，N′-双(苯基)联苯胺]中的任一种。
  14. 根据权利要求1所述的发光器件，其中，所述空穴传输层的平均表面粗糙度小于5nm。
  15. 根据权利要求14所述的发光器件，其中，所述空穴传输层的平均表面粗糙度小于1nm。
  16. 根据权利要求1所述的发光器件，还包括电子传输层，
    其中，所述电子传输层的材料包括金属氧化物。
  17. 根据权利要求16所述的发光器件，其中，所述金属氧化物包括至少两种金属。
  18. 根据权利要求17所述的发光器件，其中，所述至少两种金属包括Zn和选自Mg、Al、Ti、Zr、Li中的至少一种，并且所述Zn与所述金属氧化物的摩尔比的比值大于等于0.7。
  19. 根据权利要求17所述的发光器件，其中，所述金属氧化物为掺杂有Mg的ZnO，所述Mg与所述金属氧化物的摩尔比的比值为0.15。
  20. 根据权利要求16所述的发光器件，其中，所述电子传输层的电子迁移率大于等于10 -4cm 2/Vs。
  21. 根据权利要求20所述的发光器件，其中，10 -2≤所述第一化合物和所述第二化合物中的至少一个的空穴迁移率：所述电子传输层的电子迁移率≤10 2。
  22. 根据权利要求16所述的发光器件，还包括空穴注入层，其中，
    所述第一化合物的最高占据分子轨道的能级与所述空穴注入层的最高占据分子轨道的能级的差的绝对值小于等于0.3eV，和/或
    所述第二化合物的最高占据分子轨道的能级与所述空穴注入层的最高占据分子轨道的能级的差的绝对值小于等于0.3eV。
  23. 根据权利要求22所述的发光器件，其中，所述第一化合物的材料为聚乙烯咔唑，并且所述第一化合物与所述第二化合物的摩尔比为2∶1。
  24. 根据权利要求23所述的发光器件，其中，所述空穴注入层的材料为聚(3，4-乙烯二氧噻吩)，所述电子传输层的材料为ZnMgO，所述发光层的材料为CdSe量子点，所述阳极的材料为氧化铟锡，并且所述阴极的材料为铝。
  25. 根据权利要求1-23中任一项所述的发光器件，其中，所述发光层包括量子点。
  26. 根据权利要求1-24中任一项所述的发光器件，其中，所述发光器件为顶发射型或底发射型。
  27. 一种显示装置，包括根据权利要求1-26中任一项所述的发光器件。
  28. 一种制造发光器件的方法，包括：
    形成阳极；
    在所述阳极上施加至少混合有第一化合物和第二化合物的混合溶液以形成空穴传输层；
    在所述空穴传输层远离所述阳极的一侧形成发光层；以及
    在所述发光层远离所述空穴传输层的一侧形成阴极，
    其中，所述第二化合物的最高占据分子轨道的能级的绝对值大于等于5eV且小于等于6.5eV。
  29. 根据权利要求28所述的方法，其中，在所述阳极上施加至少混合有第一化合物和第二化合物的混合溶液以形成空穴传输层的步骤包括：
    将所述第一化合物与所述第二化合物以摩尔比为1∶1～100∶1的比例进行混合以得到所述混合溶液；以及
    利用涂覆、打印或者电流体动力喷印的方法，将所述混合溶液施加在所述阳极上以形成所述空穴传输层。
  30. 根据权利要求29所述的方法，其中，将所述第一化合物与所述第二化合物以摩尔比为1∶1～100∶1的比例进行混合以得到所述混合溶液的步骤包括：
    将由聚乙烯咔唑形成的第一化合物与所述第二化合物以摩尔比为2∶1的比例进行混合以得到所述混合溶液。
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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101510586A (zh) * 2008-02-13 2009-08-19 株式会社半导体能源研究所 发光元件、发光装置及电子设备
CN106232768A (zh) * 2014-05-30 2016-12-14 三星Sdi株式会社 有机光电元件及显示元件
CN110323342A (zh) * 2018-03-29 2019-10-11 江苏三月光电科技有限公司 一种有机电致发光器件及显示元件
JP2020096171A (ja) * 2018-09-26 2020-06-18 株式会社半導体エネルギー研究所 発光デバイス、発光装置、電子機器および照明装置

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101510586A (zh) * 2008-02-13 2009-08-19 株式会社半导体能源研究所 发光元件、发光装置及电子设备
CN106232768A (zh) * 2014-05-30 2016-12-14 三星Sdi株式会社 有机光电元件及显示元件
CN110323342A (zh) * 2018-03-29 2019-10-11 江苏三月光电科技有限公司 一种有机电致发光器件及显示元件
JP2020096171A (ja) * 2018-09-26 2020-06-18 株式会社半導体エネルギー研究所 発光デバイス、発光装置、電子機器および照明装置

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