WO2022143820A1 - Dispositif électroluminescent et son procédé de préparation - Google Patents

Dispositif électroluminescent et son procédé de préparation Download PDF

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WO2022143820A1
WO2022143820A1 PCT/CN2021/142723 CN2021142723W WO2022143820A1 WO 2022143820 A1 WO2022143820 A1 WO 2022143820A1 CN 2021142723 W CN2021142723 W CN 2021142723W WO 2022143820 A1 WO2022143820 A1 WO 2022143820A1
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light
layer
emitting device
preparing
electron transport
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PCT/CN2021/142723
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English (en)
Chinese (zh)
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王天锋
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Tcl科技集团股份有限公司
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Priority claimed from CN202011639297.8A external-priority patent/CN114695737A/zh
Priority claimed from CN202011639283.6A external-priority patent/CN114695822A/zh
Priority claimed from CN202011636859.3A external-priority patent/CN114695820A/zh
Application filed by Tcl科技集团股份有限公司 filed Critical Tcl科技集团股份有限公司
Publication of WO2022143820A1 publication Critical patent/WO2022143820A1/fr

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    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K50/00—Organic light-emitting devices
    • H10K50/10—OLEDs or polymer light-emitting diodes [PLED]
    • H10K50/11—OLEDs or polymer light-emitting diodes [PLED] characterised by the electroluminescent [EL] layers
    • H10K50/115—OLEDs or polymer light-emitting diodes [PLED] characterised by the electroluminescent [EL] layers comprising active inorganic nanostructures, e.g. luminescent quantum dots
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K71/00—Manufacture or treatment specially adapted for the organic devices covered by this subclass
    • H10K71/40—Thermal treatment, e.g. annealing in the presence of a solvent vapour

Definitions

  • the present application relates to the technical field of display devices, and in particular, to a light-emitting device and a preparation method thereof.
  • Quantum dots are nanocrystalline particles with a radius smaller than or close to the Bohr exciton radius, and their size and diameter are generally between one. Quantum dots have quantum confinement effect and can emit fluorescence when excited. Moreover, quantum dots have unique luminescence characteristics such as wide excitation peak, narrow emission peak, and tunable luminescence spectrum, which make quantum dot materials have broad application prospects in the field of optoelectronic luminescence. Quantum dot light-emitting diode (QLED) is a new type of display technology that has emerged rapidly in recent years. Quantum dot light-emitting diode is a device that uses colloidal quantum dots as the light-emitting layer. The quantum dot light-emitting layer is introduced between different conductive materials to obtain the required wavelength of light. Quantum dot light-emitting diodes have the advantages of high color gamut, self-luminescence, low startup voltage, and fast response speed.
  • OLED devices generally adopt a multi-layer device structure, and the quantum dot light-emitting layer mostly adopts quantum dot nanomaterials with a core-shell structure.
  • the organic surface ligands of quantum dot nanoparticles and the refined core-shell structure inside them make the annealing temperature not too high, so the interface roughness of the formed quantum dot layer is relatively high.
  • the annealing temperature of the quantum dot layer also limits the annealing temperature of its adjacent electron transport layer ETL, making it difficult for the electron transport material to achieve a good crystallization temperature, resulting in discontinuous internal structure of the electron transport layer and reducing the electron transport mobility.
  • the charge accumulation center is easily formed at the interface gap, which accelerates the aging of the material and seriously affects the life of the device.
  • One of the purposes of the embodiments of the present application is to provide a light-emitting device and a preparation method thereof, aiming at solving the problem of carrier recombination imbalance in optoelectronic devices.
  • the present application provides a method for preparing a light-emitting device, comprising the following steps:
  • preparing a light-emitting device including an anode, a hole functional layer, a quantum dot light-emitting layer, an electronic functional layer and a cathode that are stacked in sequence; wherein the electronic functional layer includes a metal oxide transport material;
  • the light-emitting device is subjected to ultraviolet light irradiation treatment.
  • a light-emitting device is provided, and the light-emitting device is manufactured by the above-mentioned method.
  • the beneficial effect of the method for preparing a light-emitting device is that: a pair of light-emitting devices including an anode, a hole functional layer, a quantum dot light-emitting layer, an electronic functional layer and a cathode are subjected to ultraviolet light irradiation treatment, and the ultraviolet light irradiation treatment is performed by
  • the electrons of O in the metal oxide transport material in the electron transport layer (ETL) are excited to form complexes with active metal elements such as Zn in the adjacent quantum dot light-emitting layer (QD), so that the QD-ETL interface is formed.
  • More fusion is conducive to electron injection into the light-emitting layer, and since the electrons of O in the metal oxide are coordinated with the quantum dot material, the bonding defects inside the transport layer are increased, and the electron mobility in the transport layer is improved.
  • the formed complexes and metal oxide transport materials have a strong absorption effect on UV light, so that the temperature at the interface between the electron transport layer and the light-emitting layer increases, the crystal bonding electrons in the transport layer are activated, and the crystal grows again.
  • the beneficial effect of the light-emitting device provided by the embodiments of the present application is that: since the light-emitting device is subjected to ultraviolet light irradiation treatment, the electrons of O in the metal oxide transport material in the electron transport layer are excited to form a coordination with active metal elements such as Zn in the quantum dot light-emitting layer. At the same time, the metal oxide material has a good fusion effect with the cathode after being excited by ultraviolet light.
  • the internal physical structure defects and surface roughness of the electron transport layer are reduced, the electron transport and migration efficiency is high, and the quantum dot light-emitting layer is closely combined with the electron transport layer and the cathode interface, and the electron injection efficiency is high, avoiding the accumulation of charges at the interface of the functional layer, and the device is stable. Good, long lifespan.
  • FIG. 1 is a schematic flowchart of a method for preparing a light-emitting device provided in an embodiment of the present application
  • FIG. 2 is a schematic structural diagram of a light-emitting device provided by an embodiment of the present application
  • FIG. 3 is a schematic diagram of a positive structure of a quantum dot light-emitting diode provided by an embodiment of the present application;
  • FIG. 4 is a schematic diagram of an inversion structure of a quantum dot light-emitting diode provided by an embodiment of the present application.
  • Example 5 is a graph of the efficiency of the quantum dot light-emitting diodes provided in Example 1 and Comparative Example 1 of the present application;
  • Example 6 is a current density-voltage graph of the quantum dot light-emitting diodes provided in Example 1 and Comparative Example 1 of the present application;
  • Example 7 is a graph of the brightness of the quantum dot light-emitting diodes provided in Example 1 and Comparative Example 1 of the present application;
  • Example 8 is a graph showing the efficiency of the quantum dot light-emitting diodes provided in Example 7, Example 10, Comparative Example 2 and Comparative Example 3 of the present application;
  • Example 9 is a current density-voltage graph of the quantum dot light-emitting diodes provided in Example 7, Example 10, Comparative Example 2 and Comparative Example 3 of the present application;
  • FIG. 10 is a graph showing the brightness of the quantum dot light-emitting diodes provided in Example 7, Example 10, Comparative Example 2 and Comparative Example 3 of the present application.
  • At least one means one or more
  • plural items means two or more.
  • At least one item(s) below” or similar expressions thereof refer to any combination of these items, including any combination of single item(s) or plural items(s).
  • at least one (one) of a, b, or c or, “at least one (one) of a, b, and c” can mean: a,b,c,a-b( That is, a and b), a-c, b-c, or a-b-c, where a, b, and c can be single or multiple respectively.
  • ⁇ E HTL-HIL E HOMO,HTL -E HIL
  • ⁇ E EML-HTL E HOMO,EML -E HTL
  • all energy level/work function values are absolute values, and the absolute value of the energy level is large The energy level is deep, and the absolute value of the energy level is small, the energy level is shallow.
  • a first aspect of an embodiment of the present application provides a method for preparing a light-emitting device, including the following steps:
  • a light-emitting device comprising an anode, a hole functional layer, a quantum dot light-emitting layer, an electronic functional layer, and a cathode that are sequentially stacked; wherein, the electronic functional layer includes a metal oxide transport material;
  • a light-emitting device comprising an anode, a hole functional layer, a quantum dot light-emitting layer, an electronic functional layer and a cathode is subjected to ultraviolet light irradiation treatment, and through the ultraviolet light irradiation treatment, on the one hand,
  • the electrons of O in the metal oxide transport material in the electron transport layer (ETL) are excited to form complexes with active metal elements such as Zn in the adjacent quantum dot light-emitting layer (QD), so that the QD-ETL interface is more fused.
  • the bonding defects inside the transport layer are increased, and the electron mobility in the transport layer is improved.
  • the formed complexes and metal oxide transport materials have a strong absorption effect on UV light, so that the temperature at the interface between the electron transport layer and the light-emitting layer increases, the crystal bonding electrons in the transport layer are activated, and the crystal grows again.
  • the injection rate of electrons in the light-emitting layer is faster than that of holes, resulting in the negative charge of the quantum dot material.
  • Factors such as bulk binding, Coulomb blocking effect, uneven charge distribution, and charge accumulation in the interface layer are maintained.
  • the QD-ETL interface has a large electric field intensity distribution, a high charge distribution density, and a large charge accumulation at the QD-ETL interface.
  • the negatively charged state of the quantum dot material makes the injection of electrons more and more difficult during the continuous operation of the QLED device, resulting in an imbalance between the actual injection of electrons and holes in the light-emitting layer. Furthermore, when the QLED device continues to light up and work to a stable state, the negatively charged state of the quantum dot material also tends to be stable, that is, the electrons newly captured and bound by the quantum dots reach a dynamic balance with the electrons consumed by the radiative transition. At this time, the injection rate of electrons into the light-emitting layer is much lower than that in the initial state, and the hole injection rate required to achieve the balance of charge injection in the light-emitting layer is actually relatively low.
  • the quantum dot light-emitting layer includes a quantum dot material with a core-shell structure, and the valence band top energy level difference between the outer shell layer material of the quantum dot material and the hole transport material in the hole transport layer is greater than or equal to 0.5 eV.
  • the hole injection barrier by constructing a hole injection barrier with a valence band top energy level difference of greater than or equal to 0.5 eV between the outer shell layer material of the quantum dot material and the hole transport material, the hole injection barrier is increased and the hole injection efficiency is reduced, thereby Balance the injection balance of holes and electrons in the light-emitting layer.
  • the hole injection barrier with ⁇ E EML-HTL ⁇ 0.5 eV constructed in the examples of the present application does not cause holes to be unable to be injected. Because the energy level of the outer shell layer of quantum dots will bend in the energized state, carriers can be injected through the tunneling effect; therefore, although the increase in the energy level barrier will reduce the carrier injection rate, But it does not completely hinder the final injection of carriers.
  • the core material determines the luminescence performance
  • the shell material protects and facilitates carrier injection
  • electrons and holes are injected into the core through the shell layer to emit light.
  • the band gap of the inner core is narrower than that of the outer shell, so the energy level difference between the valence band of the hole transport material and the inner core of the quantum dot is smaller than the energy level difference of the valence band of the hole transport material and the outer shell of the quantum dot. Therefore, the ⁇ E EML-HTL is greater than or equal to 0.5 eV, which can simultaneously ensure the effective injection of hole carriers into the inner core of the quantum dot material.
  • the valence band top energy level difference between the outer shell layer material of the quantum dot material and the hole transport material in the hole transport layer is 0.5-1.7 eV, that is, the ⁇ E EML-HTL is 0.5 eV-1.7 eV, and the quantum dot material is 0.5-1.7 eV.
  • the energy level barrier in this range constructed between the outer shell material and the hole transport material can be applied to device systems constructed of different hole transport materials and quantum dot materials to optimize the injection of electrons and holes in different device systems. balance.
  • ⁇ E EML-HTL different top valence band energy level differences ⁇ E EML-HTL can be set according to the specific material properties, and the carrier injection rate of holes and electrons on both sides of the light-emitting layer can be finely adjusted to balance the injection of holes and electrons.
  • the absolute value of the valence band top energy level of the hole transport material is less than or equal to 5.3 eV.
  • the absolute value of the top energy level of the valence band is adopted in the examples of the present application.
  • the shell energy level of conventional quantum dot light-emitting materials is often relatively deep (6.0eV or deeper). The energy level difference is greater than or equal to 0.5eV.
  • the mobility of the hole transport material is higher than 1 ⁇ 10 ⁇ 4 cm 2 /Vs.
  • the embodiments of the present application use hole transport materials with a mobility higher than 1 ⁇ 10 -4 cm 2 /Vs to further ensure the hole transport and migration effect, prevent charge accumulation, eliminate interface charges, and better reduce the device driving voltage and improve Device life.
  • the hole transport material is selected from at least one of: a polymer containing an aniline group, a copolymer containing a fluorene group and an aniline group, and these hole transport materials have high hole transport efficiency, It has the advantages of good stability and easy access.
  • the hole transport material includes: at least one of TFB, poly-TPD, P10, P11, P15, P12, P09, and P13, wherein the structural formula of P13 is:
  • the structural formula of P09 is:
  • the structural formula of P11 is:
  • the structural formula of poly-TPD is:
  • the structural formula of TFB is:
  • the structural formula of P12 is:
  • the structural formula of P15 is:
  • the valence band top energy level difference between the outer shell material of the quantum dot material and the hole transport material is 0.5eV ⁇ 0.7eV, in this case, the applicable hole transport material is TFB, and the quantum dot shell material is ZnSe, TFB -ZnSe device system.
  • the valence band top energy level difference between the outer shell material of the quantum dot material and the hole transport material is 0.7 eV to 1.0 eV, and the applicable hole transport material is P09, and the outer shell material of the quantum dot is ZnSe, P09 -ZnSe device system.
  • the valence band top energy level difference between the shell layer material of the quantum dot material and the hole transport material is 1.0eV ⁇ 1.4eV, and the applicable hole transport material is TFB, P13, P14, and the quantum dot shell material For ZnSe, ZnS, such as: TFB-ZnS, P13/P14-ZnSe and other device systems.
  • the valence band top energy level difference between the outer shell layer material of the quantum dot material and the hole transport material is greater than 1.4eV-1.7eV, and the device system of P09-ZnS and P13/P14-ZnS is applicable.
  • the quantum dot light-emitting layer includes a core-shell structure quantum dot material, and the outer shell layer of the quantum dot material contains zinc. Since most of the current quantum dot synthesis uses II-VI group elements, Zn element and VI group elements have better matching in terms of lattice matching and band gap, which can cover the entire visible light band, and the outer shell of the quantum dot material
  • the zinc-containing outer shell layer has suitable chemical activity, high flexibility and controllability, wide band gap, good exciton binding, high quantum efficiency, and good water-oxygen stability. In addition, the coordination effect of zinc element and O electrons is better and more stable.
  • the electrons of O of the metal oxide transport material in the electron transport layer are excited, and it is easy to form a complex with the Zn element in the QD, that is, a ZnO complex.
  • the formation of ZnO complex bonds facilitates electron injection and improves electron mobility in the electron transport layer.
  • the ZnO complex has a strong absorption effect on the wavelength of ultraviolet light, which is conducive to activating the bonding electrons, making the crystal in the ETL grow again, reducing the internal physical structure defects and surface roughness of the ETL, which is conducive to the injection of electrons and reduces the accumulation of electrons. , slow down the material aging, and help to improve the life of the device.
  • the outer shell layer of the quantum dot material includes: at least one of ZnS, ZnSe, ZnTe, CdZnS, ZnCdSe, or an alloy material formed by at least two kinds of the outer shell materials, all of which contain zinc element, and the zinc element has high activity, It has a good coordination effect with the excited O electrons in the electron transport material.
  • the step of preparing the electronic functional layer includes: sequentially preparing the first sub-electron transport layer to the N-th sub-electron transport layer on the surface of the cathode away from the substrate to form an electron transport layer; At least one sub-electron transport layer in the transport layer includes an organic transport material, at least the N-th sub-electron transport layer includes a metal oxide transport material, and N is a positive integer greater than or equal to 2.
  • an electron transport layer of a multi-layered composite structure is prepared in the device, which includes both a metal oxide sub-transport layer with high electron mobility and an organic sub-transport layer with wide energy level regulation.
  • the electron transport layer of the composite structure has the characteristics of high electron mobility and energy level matching at the same time, realizes the flexible regulation of the energy level and electron mobility of the electron transport layer, and optimizes the injection and recombination efficiency of electrons and holes in the light-emitting layer.
  • the first sub-electron transport layer close to the cathode and the N-th sub-electron transport layer close to the quantum dot light-emitting layer each independently comprise a metal oxide transport material, N It is a positive integer greater than or equal to 3 and less than or equal to 9. If the value of N is too large, the electron transport layer will be too thick, which is not conducive to electron transport.
  • the optoelectronic devices prepared in the examples of the present application are treated with ultraviolet light to promote the coordination of the metal oxide transport material in the N-th electron transport layer with the active metal elements in the quantum dots, and at the same time promote the oxidation of metals in the first electron transport layer.
  • the material transport material is coordinated with the metal element in the metal cathode to improve the fusion between the QD-ETL and the ETL-cathode interface, which is more conducive to electron injection.
  • a schematic structural diagram of the light-emitting device prepared in the embodiment of the present application includes an anode, a hole transport layer, a quantum dot light-emitting layer, and an electron transport layer that are stacked in sequence from top to bottom. (From top to bottom, it includes the Nth electron transport layer, the N-1th electron transport layer...the first electron transport layer) and the cathode, wherein the Nth electron transport layer near the quantum dot light-emitting layer is a metal oxide layer.
  • the particle size of the metal oxide transport material in the N-th electron transport layer is 2 to 4 nm, and the metal oxide particles with small particle size have a larger specific surface area and higher surface activity, and are more effective when irradiated with ultraviolet light. It is easy to cooperate with active metals in quantum dots to form a better QD-ETL interface. In addition, the metal oxide particles with small particle size have a wider band gap, which reduces the quenching of exciton emission in the light-emitting layer and improves the device efficiency.
  • the electron transport layer includes at least one sub-electron transport layer of a metal oxide transport material with a particle size of 4-8 nm.
  • the metal oxide with this particle size has high electron transfer efficiency and is conducive to electron injection and light emission. It is easier to disperse in the solution and has better film-forming properties.
  • the electron transport layer includes at least one sub-electron transport layer with a metal oxide transport material having a particle size of 4-8 nm, and the particle size of the metal oxide transport material in the Nth sub-electron transport layer is 2 to 4 nm. Since the electron mobility of metal oxides with small particle size is relatively small, which affects electron injection, and has relatively poor stability and film-forming performance, which reduces device performance, the embodiments of the present application use QD/2-4nm small particle size The combination of metal oxide/4-8nm large particle size metal oxide makes the electron transport layer have high electron migration and injection efficiency, film formation stability, QD-ETL interface fusion and other characteristics, and improves device performance.
  • the metal oxide transport material is selected from at least one of ZnO, TiO 2 , Fe 2 O 3 , SnO 2 , Ta 2 O 3 ; these metal oxide materials have high electron mobility, and Among them, the excited electrons of O have a good coordination effect with the zinc element in the QD shell.
  • the metal oxide transport material is selected from one of ZnO, TiO 2 , Fe 2 O 3 , SnO 2 , and Ta 2 O 3 , or a mixture of two or more.
  • the metal oxide transport material is selected from at least one of ZnO, TiO 2 , Fe 2 O 3 , SnO 2 , Ta 2 O 3 doped with metal elements, wherein the metal elements include aluminum, magnesium , at least one of lithium, lanthanum, yttrium, manganese, gallium, iron, chromium, and cobalt.
  • the metal oxide transport materials of the embodiments of the present application are doped with metal elements such as aluminum, magnesium, lithium, lanthanum, yttrium, manganese, gallium, iron, chromium, cobalt, etc., which are beneficial to improve the electron transport and migration efficiency of the materials.
  • the metal oxide transport material is doped with one metal element of aluminum, magnesium, lithium, lanthanum, yttrium, manganese, gallium, iron, chromium, and cobalt, or two or more of them are simultaneously doped metal element.
  • the electron mobility of the organic transport material is greater than or equal to 10 -4 cm 2 /Vs, and the organic transport material with high mobility can ensure the transfer efficiency of electrons in the transport layer, improve the injection efficiency of electrons, and avoid charges The effect of accumulation on device lifetime.
  • the organic transport material is selected from the group consisting of 8-quinolinolato-lithium (Alq 3 ), aluminum octaquinolate, fullerene derivatives PCBM, 3,5-bis(4-tert-butylphenyl) - At least one of 4-phenyl-4H-1,2,4-triazole (BPT), 1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene (TPBi) A sort of.
  • These organic transport materials can realize energy level regulation in a wide range, which is more conducive to regulating the energy levels of each functional layer of the device and improving the stability and photoelectric conversion efficiency of the device.
  • the electron transport layer has a thickness of 10-200 nm. In some specific embodiments, the thickness of the Nth sub-electron transport layer is 2 ⁇ 8 nm. This thickness satisfies device performance requirements and structural requirements. In some specific embodiments, when the thickness of the electron transport layer is less than 80 nm, the duration of the ultraviolet light irradiation treatment is 15 minutes to 45 minutes. In the examples of the present application, when the thickness of the electron transport layer is less than 80 nm, the light wave energy of the low-thickness material layer is relatively easy to penetrate. At this time, the irradiation time required to achieve the treatment effect is short, and the duration of the ultraviolet light irradiation treatment is 15 minutes to 45 minutes. minutes are appropriate.
  • the duration of the ultraviolet light irradiation treatment is 30 minutes to 90 minutes.
  • the thickness of the electron transport layer is higher than 80 nm, the light wave energy of the thick material layer is difficult to penetrate, and at this time, the illumination time required to achieve the treatment effect is longer, and the duration of the ultraviolet light irradiation treatment is 30 minutes to 90 minutes. minutes are appropriate.
  • the method further includes the step of: preparing a hole transport layer on the surface of the quantum dot light-emitting layer away from the electron transport layer, and on the surface of the hole transport layer away from the quantum dot light-emitting layer The anode is prepared on the surface.
  • a schematic structural diagram of the light-emitting device prepared in the embodiment of the present application includes an anode, a hole transport layer, a quantum dot light-emitting layer, and an electron transport layer that are stacked in sequence from top to bottom. (From top to bottom, it includes the Nth electron transport layer, the N-1th electron transport layer...the first electron transport layer) and the cathode, wherein the Nth electron transport layer near the quantum dot light-emitting layer is a metal oxide layer.
  • step S20 the step of performing ultraviolet light irradiation treatment on the light-emitting device includes: after preparing a composite layer of the quantum dot light-emitting layer and the electron transport layer between the anode and the cathode, performing ultraviolet light irradiation treatment on the composite layer .
  • a composite layer of a quantum dot light-emitting layer (QD) and an electron transport layer (ETL) is prepared between the anode and the cathode, and the composite layer is treated with ultraviolet light (UV), so that the metal oxide in the electron transport layer is transported
  • UV ultraviolet light
  • the electrons of O in the material are excited to form complexes with active metal elements such as Zn in the light-emitting layer of quantum dots, which optimizes the ETL-QD interface, reduces interface defects, and facilitates the injection of electrons from the electron transport layer to the interior of the light-emitting layer of quantum dots;
  • the bonding defects inside the electron transport layer are increased, the bonding electrons are activated, the crystal regrowth in the electron transport layer is promoted, and the electron mobility in the electron transport layer is improved.
  • a thin film transfer method is used to prepare a composite layer of the quantum dot light-emitting layer and the electron transport layer between the anode and the cathode, which specifically includes the steps of: sequentially depositing and preparing the quantum dot light-emitting layer and the electron transport layer on the substrate, After the composite layer of the quantum dot light-emitting layer and the electron transport layer is subjected to ultraviolet light irradiation treatment, the composite layer of the quantum dot light-emitting layer and the electron transport layer is transferred to the substrate prepared with the cathode, and then the surface of the quantum dot light-emitting layer is sequentially prepared.
  • a hole transport layer, a hole injection layer and an anode are used to obtain a light-emitting device with an inversion structure.
  • the composite layer of the quantum dot light-emitting layer and the electron transport layer is transferred to a substrate prepared in sequence with an anode, a hole injection layer and a hole transport layer, and then a cathode is prepared on the surface of the electron transport layer to obtain a positive-type light-emitting structure. device.
  • a solution deposition method is used to prepare a laminated composite structure of a quantum dot light-emitting layer and an electron transport layer between the anode and the cathode.
  • the specific steps include: preparing an anode on a substrate; depositing a hole injection layer on the surface of the anode away from the substrate; depositing and preparing holes on the surface of the hole injection layer away from the anode transport layer; deposit and prepare a quantum dot light-emitting layer on one side of the hole transport layer; prepare an electron transport layer on the surface of the quantum dot light-emitting layer away from the hole transport layer, and irradiate the electron transport layer with ultraviolet light to obtain quantum dots
  • a composite layer of a light-emitting layer and an electron transport layer; a cathode is deposited on the surface of the electron transport layer to obtain an optoelectronic device.
  • the specific steps include: preparing a cathode on a substrate; preparing an electron transport layer on the surface of the cathode; preparing a quantum dot light-emitting layer on the side surface of the electron transport layer away from the cathode, and subjecting the quantum dot light-emitting layer to ultraviolet light Irradiation treatment to obtain a composite layer of the quantum dot light-emitting layer and the electron transport layer; a hole transport layer, a hole injection layer and an anode are sequentially prepared on the surface of the quantum dot light-emitting layer away from the electron transport layer to obtain an optoelectronic device.
  • the step of irradiating with ultraviolet light includes: irradiating the light-emitting device for 10-60 minutes under the condition that the wavelength of the ultraviolet light is 250-420 nm and the light wave density is 10-300 mJ/cm 2 .
  • the ultraviolet irradiation treatment conditions in the examples of this application can better promote the coordination of O atoms in the metal oxide transport material in the ETL with elements such as zinc in the outer shell layer of the quantum dots, and not only optimize the electron transport layer and the quantum dot light-emitting layer and
  • the interface gap between the cathodes can improve the efficiency of electron migration and injection, and can better increase the internal bonding of ETL, promote the re-growth of internal crystals, reduce internal crystal structure defects and surface roughness, and improve electron mobility.
  • the conditions of the ultraviolet light irradiation treatment include: performing in an environment where the content of H 2 O is less than 1 ppm and the temperature is 80-120° C.
  • the ultraviolet light irradiation treatment is carried out in an environment where the H 2 O content is less than 1 ppm and the temperature is 80-120° C., so as to avoid the excessive water content in the environment, which will cause the surface of the quantum dot material to be hydrolyzed during the light treatment process, which will affect the performance of the material.
  • the heating environment of 80-120 °C is conducive to promoting the formation of bonds between the electrons excited by O and the zinc ions, and is also conducive to the activation of the bonding electrons.
  • the step of ultraviolet light irradiation treatment includes: using ultraviolet light waves with a wavelength of 320-420 nm and an optical wave density of 10-150 mJ/cm 2 to perform irradiation treatment from the anode side for 10-60 minutes.
  • the functional layers such as anode, holes and QDs have little damage to the light wave. Longer, less dense light waves are irradiated.
  • the step of irradiating with ultraviolet light includes: using ultraviolet light waves with a wavelength of 250-320 nm and an optical wave density of 100-200 mJ/cm 2 to perform irradiation treatment from the cathode side for 10-60 minutes.
  • the metal cathode has a large damage to the UV light wave, and the light wave directly acts on the ETL layer after passing through the cathode layer, and will not affect the materials of other functional layers such as holes.
  • the wavelength of ultraviolet light irradiation treatment is 250-355 nm
  • the optical wave density is 50-150 mJ/cm 2 .
  • the bond energy of ZnS is about 3.5eV
  • the bond energy of ZnO is about 3.3eV.
  • the transfer of the bonding charges of electron transport materials such as ZnS and ZnO in the material shell makes the zinc element in the shell layer and the O element in the electron transport material have a better coordination effect, forming a complex between the electron transport material and the quantum dot material.
  • the wavelength of ultraviolet light irradiation treatment is 280-375 nm, and the optical wave density is 30-120 mJ/cm 2 .
  • the bond energy of ZnSe is about 2.9eV, and the bond energy of ZnO is about 3.3eV, and the wavelength of ultraviolet light irradiation treatment is 280 ⁇ 375nm, and the light wave density is 30 ⁇ 120mJ/ cm2 .
  • the wavelength of ultraviolet light irradiation treatment is 250-375 nm
  • the optical wave density is 30-150 mJ/cm 2 .
  • the bond energy of ZnSeS is about 2.7eV
  • the bond energy of ZnO is about 3.3eV
  • the wavelength of ultraviolet light irradiation treatment is 250 ⁇ 375nm
  • the optical wave density is 30 ⁇ 150mJ/ cm2
  • the quantum dot light-emitting layer has a thickness of 8-100 nm.
  • the hole transport layer has a thickness of 10-150 nm. This thickness satisfies device performance requirements and structural requirements.
  • the electron functional layer, the light emitting layer, and the hole functional layer in the device can be designed with appropriate thicknesses according to the characteristics of the device in the above embodiments.
  • the thickness of the outer shell layer of the quantum dot material is 0.2-6.0 nm, which ensures the stability of the inner layer material of the quantum dot and the carrier injection effect, and at the same time ensures the zinc element and the metal oxide in the outer shell layer. Coordination effects of O element in transport materials.
  • the cathode in the above step S10, in the substrate on which the cathode is deposited, includes at least one metal material or at least two alloy materials of Mg, Ag, Al, and Ca. Under the condition of ultraviolet light irradiation, These cathode metal materials have good fusion effects with metal oxide electron transport materials, which can reduce the electron injection barrier and improve the efficiency of electron injection into optoelectronic devices.
  • the preparation of the light-emitting device in the embodiments of the present application includes the steps:
  • step S50 in order to obtain a high-quality zinc oxide nanomaterial thin film, the ITO substrate needs to undergo a pretreatment process.
  • the basic specific treatment steps include: cleaning the ITO conductive glass with a detergent to preliminarily remove the stains on the surface, and then ultrasonically cleaning in deionized water, acetone, anhydrous ethanol, and deionized water for 20 minutes respectively to remove impurities on the surface. , and finally blow dry with high-purity nitrogen to obtain the ITO positive electrode.
  • the step of growing the hole transport layer includes: on the ITO substrate, depositing the prepared solution of the hole transport material through processes such as drop coating, spin coating, soaking, coating, printing, evaporation, etc. Film formation; the film thickness is controlled by adjusting the concentration of the solution, deposition rate and deposition time, and then thermal annealing at an appropriate temperature.
  • the step of depositing the quantum dot light-emitting layer on the hole transport layer includes: on the substrate on which the hole transport layer has been deposited, a solution of a light-emitting substance prepared with a certain concentration is applied by drop coating, spin coating, soaking , coating, printing, evaporation and other processes to deposit the film, and control the thickness of the light-emitting layer by adjusting the concentration of the solution, the deposition speed and the deposition time, about 20-60nm, and dry at an appropriate temperature.
  • the step of depositing the electron transport layer on the quantum dot light-emitting layer includes: the Nth electron transport layer is a metal oxide transport material: on the substrate on which the quantum dot light-emitting layer has been deposited, a certain amount of The concentrated metal oxide transport material solution is deposited into a film by processes such as drop coating, spin coating, soaking, coating, printing, evaporation, etc.
  • the deposition speed for example, the rotation speed is between 3000 and 5000 rpm
  • the thickness of the electron transport layer is controlled by the deposition time, about 20 to 60 nm, and then annealed at 150 to 200 °C to form a film to fully remove the solvent.
  • Sub-electron transport layers such as organic transport materials and metal oxide transport materials are prepared by redepositing on the surface of the N-th sub-electron transport layer.
  • the cathode preparation step includes: placing the substrate on which each functional layer has been deposited into an evaporation chamber and thermally evaporated a layer of 60-100 nm metal silver or aluminum as a cathode through a mask plate.
  • step S100 in an environment where the H 2 O content is less than 1 ppm and the temperature is 80-120° C., ultraviolet light with a wavelength of 250-420 nm and an optical wave density of 10-300 mJ/cm 2 is used to vertically conduct the photoelectric device. Irradiate for 10 to 60 minutes.
  • the obtained QLED device is packaged, and the package process can be packaged by a common machine or by manual packaging.
  • the oxygen content and water content are both lower than 0.1ppm to ensure the stability of the device.
  • the preparation steps of the light-emitting device in the embodiments of the present application may also adopt the preparation sequence of the inversion device structure, and the electron transport layer, the quantum dot light-emitting layer, the hole transport layer, the electron transport layer, the quantum dot light-emitting layer, the hole transport layer, the hole injection layer and anode.
  • a second aspect of the embodiments of the present application provides a light-emitting device, and the light-emitting device is manufactured by the above method.
  • the light-emitting device since the light-emitting device is subjected to ultraviolet light irradiation treatment, the electrons of O in the metal oxide transport material in the electron transport layer are excited to form complexes with active metal elements such as Zn in the quantum dot light-emitting layer, and simultaneously
  • the metal oxide material has a good fusion effect with the cathode after being excited by ultraviolet light.
  • the internal physical structure defects and surface roughness of the electron transport layer are reduced, the electron transport and migration efficiency is high, and the quantum dot light-emitting layer is closely combined with the electron transport layer and the cathode interface, and the electron injection efficiency is high, avoiding the accumulation of charges at the interface of the functional layer, and the device is stable. Good, long lifespan.
  • the light-emitting device is not limited by the device structure, and may be a device with a positive structure or a device with an inversion structure.
  • the positive structure light-emitting device includes a stacked structure of oppositely disposed anode and cathode, a light-emitting layer disposed between the anode and the cathode, and the anode is disposed on the substrate.
  • a hole functional layer such as a hole injection layer, a hole transport layer, and an electron blocking layer can also be arranged between the anode and the light-emitting layer; an electron transport layer, an electron injection layer, and a hole blocking layer can also be arranged between the cathode and the light-emitting layer.
  • the isoelectronic functional layer is shown in Figure 3.
  • the light emitting device includes a substrate, an anode disposed on the surface of the substrate, a hole transport layer disposed on the surface of the anode, a light emitting layer disposed on the surface of the hole transport layer, An electron transport layer on the surface of the layer and a cathode disposed on the surface of the electron transport layer.
  • the inversion structure light-emitting device includes a stacked structure of an anode and a cathode disposed oppositely, a light-emitting layer disposed between the anode and the cathode, and the cathode disposed on the substrate.
  • a hole functional layer such as a hole injection layer, a hole transport layer, and an electron blocking layer can also be arranged between the anode and the light-emitting layer; an electron transport layer, an electron injection layer, and a hole blocking layer can also be arranged between the cathode and the light-emitting layer.
  • the isoelectronic functional layer is shown in Figure 4.
  • the light emitting device includes a substrate, a cathode disposed on the surface of the substrate, an electron transport layer disposed on the surface of the cathode, a light emitting layer disposed on the surface of the electron transport layer,
  • the hole transport layer is an anode disposed on the surface of the hole transport layer.
  • the choice of the substrate is not limited, and a rigid substrate or a flexible substrate may be used.
  • the rigid substrate includes, but is not limited to, one or more of glass and metal foil.
  • the flexible substrate includes, but is not limited to, polyethylene terephthalate (PET), polyethylene terephthalate (PEN), polyetheretherketone (PEEK), polystyrene (PS), polyethersulfone (PES), polycarbonate (PC), polyarylate (PAT), polyarylate (PAR), polyimide (PI), polyvinyl chloride (PV), poly One or more of ethylene (PE), polyvinylpyrrolidone (PVP), and textile fibers.
  • PET polyethylene terephthalate
  • PEN polyethylene terephthalate
  • PEEK polyetheretherketone
  • PS polystyrene
  • PS polyethersulfone
  • PC polycarbonate
  • PAT polyarylate
  • PAR polyarylate
  • PI polyimide
  • PV polyviny
  • the choice of anode material is not limited and can be selected from doped metal oxides, including but not limited to indium doped tin oxide (ITO), fluorine doped tin oxide (FTO), antimony doped tin oxide (ATO), Aluminum-Doped Zinc Oxide (AZO), Gallium-Doped Zinc Oxide (GZO), Indium-Doped Zinc Oxide (IZO), Magnesium-Doped Zinc Oxide (MZO), Aluminum-Doped Magnesium Oxide (AMO) one or more.
  • doped metal oxides including but not limited to indium doped tin oxide (ITO), fluorine doped tin oxide (FTO), antimony doped tin oxide (ATO), Aluminum-Doped Zinc Oxide (AZO), Gallium-Doped Zinc Oxide (GZO), Indium-Doped Zinc Oxide (IZO), Magnesium-Doped Zinc Oxide (MZO), Aluminum-Doped Magnesium Oxide (AMO)
  • the hole injection layer includes, but is not limited to, one or more of organic hole injection materials, doped or undoped transition metal oxides, doped or undoped metal chalcogenides .
  • organic hole injection materials include, but are not limited to, poly(3,4-ethylenedioxythiophene)-polystyrenesulfonic acid (PEDOT:PSS), copper phthalocyanine (CuPc), 2,3, 5,6-Tetrafluoro-7,7',8,8'-tetracyanoquinone-dimethane (F4-TCNQ), 2,3,6,7,10,11-hexacyano-1,4,5 One or more of ,8,9,12-hexaazatriphenylene (HATCN).
  • PDOT:PSS poly(3,4-ethylenedioxythiophene)-polystyrenesulfonic acid
  • CuPc copper phthalocyanine
  • F4-TCNQ 2,3,6,7,10,11-hexacyano-1,
  • transition metal oxides include, but are not limited to, one or more of MoO 3 , VO 2 , WO 3 , CrO 3 , and CuO.
  • the metal chalcogenide compounds include, but are not limited to, one or more of MoS 2 , MoSe 2 , WS 2 , WSe 2 , and CuS.
  • the hole transport layer may be selected from organic materials with hole transport capability and/or inorganic materials with hole transport capability.
  • the organic material with hole transport capability includes, but is not limited to, poly(9,9-dioctylfluorene-CO-N-(4-butylphenyl)diphenylamine) (TFB), poly(9,9-dioctylfluorene-CO-N-(4-butylphenyl)diphenylamine) Vinylcarbazole (PVK), poly(N,N'bis(4-butylphenyl)-N,N'-bis(phenyl)benzidine) (poly-TPD), poly(9,9-dioctyl) Fluorene-co-bis-N,N-phenyl-1,4-phenylenediamine) (PFB), 4,4,4"-tris(carbazol-9-yl)triphenylamine (TCTA), 4, 4'-bis
  • inorganic materials with hole transport capability include but are not limited to doped graphene, undoped graphene, C60, doped or undoped MoO 3 , VO 2 One or more of , WO 3 , CrO 3 , CuO, MoS 2 , MoSe 2 , WS 2 , WSe 2 , and CuS.
  • the light-emitting layer includes the quantum dot material in the above embodiments, the quantum dot material is a core-shell structure quantum dot material, and the outer shell layer of the quantum dot material contains zinc.
  • the outer shell layer of the quantum dot material includes: at least one of ZnS, ZnSe, ZnTe, CdZnS, and ZnCdSe, or an alloy material formed by at least two of them.
  • the particle size of the quantum dot material is in the range of 2 to 10 nm. If the particle size is too small, the film-forming property of the quantum dot material becomes poor, and the energy resonance transfer effect between the quantum dot particles is significant, which is not conducive to the application of the material. , the particle size is too large, the quantum effect of the quantum dot material is weakened, resulting in a decrease in the optoelectronic properties of the material.
  • the material of the electron transport layer adopts the electron transport layer of the above-mentioned laminated composite structure.
  • the cathode material may be one or more of various conductive carbon materials, conductive metal oxide materials, and metallic materials.
  • conductive carbon materials include, but are not limited to, doped or undoped carbon nanotubes, doped or undoped graphene, doped or undoped graphene oxide, C60, graphite, carbon fiber, many Empty carbon, or a mixture thereof.
  • the conductive metal oxide material includes, but is not limited to, ITO, FTO, ATO, AZO, or mixtures thereof.
  • the metal materials include, but are not limited to, Al, Ag, Cu, Mo, Au, or their alloys; among the metal materials, their forms include but are not limited to dense films, nanowires, nanospheres, nanometers Rods, nano cones, nano hollow spheres, or their mixtures; the cathode is Ag, Al.
  • a light-emitting diode comprising the following preparation steps:
  • ITO anode Provides ITO anode, and pre-treat the anode: use alkaline washing solution (preferably PH>10 ultrasonic for 15 min, deionized water ultrasonic for 15 min twice, isopropanol ultrasonic cleaning for 15 min, dry at 80 °C for 2 h, ozone ultraviolet Process for 15min.
  • alkaline washing solution preferably PH>10 ultrasonic for 15 min, deionized water ultrasonic for 15 min twice, isopropanol ultrasonic cleaning for 15 min, dry at 80 °C for 2 h, ozone ultraviolet Process for 15min.
  • step (2) (2) forming a hole injection layer on the anode of step (1): under an electric field, spin-coating the PEDOT:PSS solution on the anode, spin-coating at 5000 rpm for 40 s, and then annealing at 150° C. for 15 min to form a hole-injecting layer; wherein , the action direction of the electric field is perpendicular to the anode and toward the hole injection layer, and the electric field strength is 10 4 V/cm.
  • Al is evaporated on the electron transport layer by an evaporation method to form an Al electrode with a thickness of 60-150 nm.
  • UV treatment was performed on the prepared device, under the environment of H 2 O content less than 1 ppm and temperature of 100°C, vertical irradiation from the Al electrode side, UV wavelength 250nm, intensity 300mJ/cm 2 , UV time 30min.
  • a light-emitting diode the difference between its preparation steps and Example 1 is: in step (7), UV treatment is performed on the prepared device, vertical irradiation from the ITO anode side, UV wavelength 420nm, intensity 100mJ/cm 2 , UV time 30min .
  • a light-emitting diode the preparation steps of which are different from those in Example 1 are: TiO 2 is used in step (5).
  • a light-emitting diode the preparation steps of which are different from those in Example 1 are: ZnMgO is used in step (5).
  • a light-emitting diode the preparation steps of which are different from those in Example 1 are: CdZnSe/ZnSe is used in step (4).
  • the ultraviolet illumination conditions are as follows: UV light with a UV wavelength of 320 nm and an intensity of 300 mJ/cm 2 is used to vertically irradiate the light-emitting layer for 30 minutes.
  • a light-emitting diode the preparation steps of which are different from those in Example 1 are: CdZnSe/ZnSeS is used in step (4).
  • the ultraviolet light conditions are: 340 nm, UV light with an intensity of 300 mJ/cm 2 vertically irradiates the light-emitting layer for 30 minutes.
  • a light-emitting diode comprising the following preparation steps:
  • step (2) forming the electron transport layer of the composite structure on the Al cathode of step (1): take the ZnO nanoparticle solution (concentration is 30mg/mL, the solvent is ethanol), put the ZnO nanoparticle solution in a glove box (water oxygen content is less than 0.1ppm), spin-coated on the low electrode at 4000rpm, and annealed at 80°C for 30min to form a ZnO layer. Then, take the Alq3 solution (concentration is 10 mg/mL, the solvent is dimethylformamide), spin-coat the Alq3 solution on the ZnO layer at 1000 rpm, and anneal at 80 °C for 30 min to form the Alq3 layer.
  • a hole transport layer on the light-emitting layer under an electric field, spin-coat TFB solution (concentration of 8 mg/mL, solvent is chlorobenzene) on the light-emitting layer, spin-coat at 3000 rpm for 30 s, and then anneal at 80 °C for 30 min.
  • a hole transport layer was formed; wherein the direction of action of the electric field was perpendicular to the anode and toward the hole transport layer, and the electric field strength was 104 V/cm.
  • An ITO anode is formed on the hole injection layer.
  • UV treatment was performed on the prepared device, under the environment of H 2 O content less than 1 ppm and temperature of 100°C, vertical irradiation from the Al electrode side, UV wavelength 250nm, intensity 200mJ/cm 2 , UV time 30min.
  • a light-emitting diode the preparation steps of which are different from those in Example 1 are: in step (2), PCBM is used to prepare an organic electron transport layer.
  • a light-emitting diode the preparation steps of which are different from those in Example 1 are: in step (2), ZnMgO is used to prepare an inorganic electron transport layer.
  • a light-emitting diode the preparation steps of which are different from those in Example 1 are: Alq3+ZnO (particle size is 5.5 nm)+ZnO (particle size is 3 nm) is used in step (2).
  • a light-emitting diode the preparation steps of which are different from those in Example 1 are: CdZnSe/ZnSe is used in step (3).
  • the ultraviolet illumination conditions are as follows: UV light with a UV wavelength of 320 nm and an intensity of 300 mJ/cm 2 is used to vertically irradiate the light-emitting layer for 30 minutes.
  • a light-emitting diode the preparation steps of which are different from those in Example 1 are: CdZnSe/ZnSeS is used in step (3).
  • the ultraviolet light conditions are: 340 nm, UV light with an intensity of 300 mJ/cm 2 , vertically irradiating the light-emitting layer for 30 minutes.
  • the two kinds of quantum dots used in Examples 13 to 20 of the present application are: blue QD1 with CdZnS outer shell (the inner core is CdZnSe, the middle shell is ZnSe, the outer shell thickness is 1.5 nm, and the top energy level of the valence band is -6.2 eV) , blue QD2 with ZnS outer shell (inner core is CdZnSe, intermediate shell is ZnSe, ZnS shell thickness is 0.3 nm, valence band top energy level is -6.5 eV).
  • the blue QD3 with ZnSeS shell (the inner core is CdZnSe, the middle shell is ZnSe) hole transport materials are P9 (E HOMO :-5.1eV), P15 (E HOMO :-5.8eV), the hole injection layer is PEDOT : PSS (E HOMO : -5.1 eV), the electron transport layer adopts ZnO and TiO 2 , as shown in Table 2 below.
  • the optoelectronic devices in Examples 13 to 20 of the present application are all UV treated: in an environment where the H 2 O content is less than 1 ppm and the temperature is 100° C., vertical irradiation from the Al electrode side, UV wavelength 250 nm, intensity 300 mJ/cm 2 , UV time 30min.
  • Example 2 A light-emitting diode, the difference between its preparation steps and Example 1 is that it does not have step (7) UV treatment). Comparative Example 2
  • a light-emitting diode whose preparation steps differ from those of Example 7 in that it is not UV-treated in step (8).
  • step (2) the electron transport layer only contains a ZnO metal oxide layer
  • a light-emitting diode the preparation steps of which are different from those in Example 1 are: in step (2), the electron transport layer only contains an Alq3 organic transport layer.
  • test index and the test method are as follows, and the test results are shown in the following table and accompanying drawings:
  • the specific calculation formula is as follows:
  • ⁇ e is the optical output coupling efficiency
  • ⁇ r is the ratio of the number of recombined carriers to the number of injected carriers
  • ⁇ is the ratio of the number of excitons that generate photons to the total number of excitons
  • KR is the radiation process rate.
  • KNR is the nonradiative process rate. Test conditions: At room temperature, the air humidity is 30-60%.
  • Luminance (L) is the ratio (cd/m2) of the luminous flux of the light-emitting surface in the specified direction to the area of the luminous flux perpendicular to the specified direction.
  • the life test adopts the constant current method, under the constant current of 50mA/ cm2 , the silicon photosystem is used to test the brightness change of the device, and the time when the brightness of the device starts from the highest point and decays to 95% of the highest brightness is recorded LT95, Then extrapolate the 1000nit LT95S life of the device through the empirical formula:
  • This method is convenient for comparing the lifetime of devices with different brightness levels, and has a wide range of applications in practical optoelectronic devices.
  • the energy level test method of each material in the examples of the present application after spin-coating each functional layer material to form a film, the energy level test is carried out by UPS (ultraviolet photoelectron spectroscopy) method.
  • UPS ultraviolet photoelectron spectroscopy
  • Valence band top VB(HOMO): E HOMO E F-HOMO + ⁇ , where E F-HOMO is the difference between the material HOMO(VB) and the Fermi level, corresponding to the first occurrence of the low binding energy end in the binding energy spectrum the starting edge of a peak;
  • E LOMO E HOMO -E HOMO-LOMO
  • E HOMO-LOMO is the band gap of the material, obtained from UV-Vis (ultraviolet absorption spectrum).
  • Example 1 Part number Quantum Dot Shell Electron transport layer (particle size) EQE(%) LT95 (hours) Comparative Example 1 ZnS ZnO(5.5nm) 1.80% 7.19 Example 1 ZnS ZnO(5.5nm) 4.30% 15.2 Example 2 ZnS ZnO(5.5nm) 3.10% 9.8 Example 3 ZnS TiO 2 (5.5nm) 5.10% 10.2 Example 4 ZnS ZnMgO(5.5nm) 6.10% 39 Example 5 ZnSe ZnO(5.5nm) 3.80% 12.4 Example 6 ZnSeS ZnO(5.5nm) 4.00% 13
  • the ⁇ E EML-HTL barrier difference increases from 0.4eV to 0.7eV, the device The lifespan has been significantly improved, the 1000nit LT95S lifespan has been increased from 1.2 to 9.3. It can be seen that whether the HTL or EML material is adjusted to increase the valence band top energy level difference ⁇ E EML-HTL to more than 0.5 eV, the device injection balance is optimized, and the device lifetime can be enhanced. It shows that reducing the hole injection efficiency by increasing the hole injection barrier can better balance the injection balance of holes and electrons in the light-emitting layer, and improve the luminous efficiency and luminous life of the device.

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Abstract

La présente invention concerne un dispositif électroluminescent et un procédé de préparation associé. Le procédé de préparation du dispositif électroluminescent comprend les étapes suivantes : préparation d'un dispositif électroluminescent comprenant une anode, une couche fonctionnelle de trous, une couche électroluminescente à points quantiques, une couche fonctionnelle d'électrons et une cathode qui sont empilées séquentiellement, la couche fonctionnelle d'électrons comprenant un matériau de transport d'oxyde métallique; et réalisation d'un traitement par irradiation ultraviolette sur le dispositif électroluminescent. Selon le procédé de préparation du dispositif électroluminescent de la présente invention, un traitement par irradiation ultraviolette est effectué sur le dispositif électroluminescent de sorte que les électrons de O dans le matériau de transport d'oxyde métallique sont excités pour former un complexe avec des éléments métalliques actifs dans le matériau à points quantiques et, en même temps, après avoir été excité par la lumière ultraviolette, le matériau d'oxyde métallique fusionne avec la cathode. Les défauts de structure physique interne et la rugosité de surface de la couche de transport d'électrons sont réduits, l'efficacité de la migration de transport d'électrons est élevée, la couche électroluminescente à points quantiques est étroitement combinée à la couche de transport d'électrons et à l'interface de cathode, l'efficacité d'injection d'électrons est élevée, l'accumulation de charge d'interface des couches fonctionnelles est évitée et le dispositif a une bonne stabilité et une longue durée de vie.
PCT/CN2021/142723 2020-12-31 2021-12-29 Dispositif électroluminescent et son procédé de préparation WO2022143820A1 (fr)

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CN202011636859.3A CN114695820A (zh) 2020-12-31 2020-12-31 发光器件及其制备方法
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CN106450042A (zh) * 2016-09-26 2017-02-22 Tcl集团股份有限公司 一种金属氧化物、qled及制备方法
CN109935724A (zh) * 2017-12-15 2019-06-25 Tcl集团股份有限公司 量子点发光层及其制备方法和应用
CN111384257A (zh) * 2018-12-28 2020-07-07 广东聚华印刷显示技术有限公司 量子点电致发光器件及显示器
CN111384268A (zh) * 2018-12-29 2020-07-07 Tcl集团股份有限公司 量子点发光二极管的制备方法及量子点墨水
US10826011B1 (en) * 2019-07-23 2020-11-03 Sharp Kabushiki Kaisha QLED fabricated by patterning with phase separated emissive layer

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106450042A (zh) * 2016-09-26 2017-02-22 Tcl集团股份有限公司 一种金属氧化物、qled及制备方法
CN109935724A (zh) * 2017-12-15 2019-06-25 Tcl集团股份有限公司 量子点发光层及其制备方法和应用
CN111384257A (zh) * 2018-12-28 2020-07-07 广东聚华印刷显示技术有限公司 量子点电致发光器件及显示器
CN111384268A (zh) * 2018-12-29 2020-07-07 Tcl集团股份有限公司 量子点发光二极管的制备方法及量子点墨水
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