Photoelectric device, preparation method thereof and display device

Abstract

The invention belongs to the technical field of display, and relates to a photoelectric device, a preparation method thereof and a display device, and the photoelectric device comprises a first electrode, an active layer, an electronic function layer, an auxiliary layer and a second electrode which are sequentially stacked. The auxiliary layer is arranged between the electronic functional layer and the second electrode, and the electron mobility of the auxiliary layer is smaller than that of the electronic functional layer, so that the injection balance of holes and electrons in the active layer can be improved, the luminous efficiency of the photoelectric device is improved, and the service life of the photoelectric device is prolonged.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of display, more particularly, to a photoelectric device and a preparation method therefor, and a display device. BACKGROUND

[0002] Quantum dot light emitting diode (QLED) is a new display technology that has rapidly emerged in recent years. QLED is a device in which colloidal quantum dots are used as a light emitting layer. By introducing a quantum dot light emitting layer between different conductive materials, light of a desired wavelength can be obtained.

[0003] In the prior art, the electron injection capability of an electronic functional layer to a quantum dot light emitting layer is generally stronger than the hole injection capability, and the phenomenon of unbalanced hole injection and electron injection is prone to occur, which affects the light emitting efficiency and service life of the photoelectric device. SUMMARY

[0004] To solve the above technical problems, the present application provides a photoelectric device, which adopts the technical scheme as follows:

[0005] A photoelectric device includes a first electrode, an active layer, an electronic functional layer, an auxiliary layer, and a second electrode, which are sequentially stacked.

[0006] The material of the auxiliary layer includes a semiconductor material, and the electron mobility of the auxiliary layer is less than the electron mobility of the electronic functional layer.

[0007] Correspondingly, the present application provides a preparation method of a photoelectric device, which includes the following preparation steps:

[0008] A first pre-device is provided, which includes a first electrode, an active layer, and an electronic functional layer, which are sequentially stacked.

[0009] An auxiliary layer is formed on the electronic functional layer.

[0010] A second electrode is formed on the side of the auxiliary layer away from the electronic functional layer, so as to obtain the photoelectric device.

[0011] Alternatively,

[0012] A second pre-device is provided, which includes a second electrode and an electronic functional layer, which are sequentially stacked.

[0013] An auxiliary layer is formed on the electronic functional layer.

[0014] An active layer and a first electrode are sequentially formed on the side of the auxiliary layer away from the electronic functional layer, so as to obtain the photoelectric device.

[0015] The auxiliary layer is made of a semiconductor material, and the electron mobility of the auxiliary layer is less than the electron mobility of the electron functional layer.

[0016] Accordingly, the application provides a display device comprising the optoelectronic device or prepared by the method.

[0017] Compared with the prior art, the application has the following advantages:

[0018] The application can improve the injection balance of holes and electrons in the active layer by setting the auxiliary layer between the electron functional layer and the second electrode, thereby improving the light emitting efficiency and service life of the optoelectronic device. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the solutions in the application or prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative effort.

[0020] Figure 1 is a structural diagram of the optoelectronic device of the application;

[0021] Figure 2 is a flow chart of the preparation method of the optoelectronic device of the application.

[0022] Reference signs:

[0023] 1, first electrode; 2, hole injection layer; 3, hole transport layer; 4, active layer; 5, electron functional layer; 6, auxiliary layer; 7, second electrode; 8, light extraction layer; 9, encapsulation layer. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the application will be described clearly and completely below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only some of the embodiments of the application, but not all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative effort fall within the scope of the application. In addition, it should be understood that the specific embodiments described herein are only used to illustrate and explain the application, and are not used to limit the application.

[0025] In the present application, the orientation words such as "upper" and "lower" generally refer to the upper and lower in the actual use or working state of the device, specifically the drawing surface direction in the drawings, unless otherwise specified. In addition, in the description of the present application, the term "comprising" means "including but not limited to". The terms first, second, third, etc. are only used as labels and do not impose numerical requirements or establish an order.

[0026] In the present application, the association relationship of the associated objects is described by "and / or", which means that there can be three kinds of relationships, for example, A and / or B can represent the following cases: A exists alone, A and B exist together, and B exists alone. Wherein A and B can be singular or plural.

[0027] In the present application, "at least one" means one or more, and "multiple" means two or more. "At least one", "at least one of the following" or the like means any combination of the items, including single item or any combination of multiple items. For example, "at least one of a, b, or c", or "at least one of a, b, and c" can represent a, b, c, a-b (i.e. a and b), a-c, b-c, or a-b-c, wherein a, b, and c can be single or multiple.

[0028] Various embodiments of the present application can exist in the form of a range; it should be understood that the description in the form of a range is only for the convenience and brevity, and should not be understood as a hard limit on the scope of the present application; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single values within the range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as single numbers within the range, such as 1, 2, 3, 4, 5, and 6, regardless of the range. In addition, whenever a numerical range is indicated in the present application, it refers to any cited number (fraction or integer) within the indicated range.

[0029] In existing optoelectronic devices, the electron functional layer 5 is mainly inorganic material, and the electron injection rate is generally much larger than the hole injection rate, which easily causes imbalance between electron and hole injection in the active layer, thereby limiting the improvement of light-emitting efficiency and service life of the optoelectronic device.

[0030] Please refer to Figure 1 To solve the above problems, the present application provides an optoelectronic device, which comprises a first electrode 1, an active layer 4, an electron functional layer 5, an auxiliary layer 6 and a second electrode 7 which are sequentially stacked; wherein the electron mobility of the auxiliary layer 6 is less than the electron mobility of the electron functional layer 5.

[0031] Further, the electron mobility of the electron functional layer 5 is 10 -2 ~ 10 -1 cm 2 / (V*S), specifically, the electron mobility of the electron functional layer 5 can be in a range between any one or any two of 0.01 cm 2 / (V*S), 0.03 cm 2 / (V*S), 0.05 cm 2 / (V*S), 0.07 cm 2 / (V*S), 0.09 cm 2 / (V*S), 0.1 cm 2 / (V*S), etc.

[0032] Further, the electron mobility of the auxiliary layer 6 is 10 -3 ~ 10 -2 cm 2 / (V*S), specifically, the electron mobility of the auxiliary layer 6 can be in a range between any one or any two of 0.001 cm 2 / (V*S), 0.003 cm 2 / (V*S), 0.005 cm 2 / (V*S), 0.007 cm 2 / (V*S), 0.009 cm 2 / (V*S), 0.01 cm 2 / (V*S), etc.

[0033] In the embodiment, the electron mobility of the auxiliary layer 6 is less than the electron mobility of the electron functional layer 5, which increases the injection barrier of the electrons from the second electrode 7 to the electron functional layer 5, and reduces the electron transport efficiency from the electron functional layer 5 to the active layer 4, effectively improves the problem that the electron injection and transport rate is much greater than the hole injection and transport rate, realizes the balance of the electron and hole injection of the active layer 4, and thus improves the light emitting efficiency and service life of the optoelectronic device.

[0034] In the embodiment, the Hall tester can be used to test the electron mobility of the auxiliary layer 6 and the electron functional layer 5, and the test conditions are as follows: the sample thickness is 100 nm ~ 300 nm, the sample size is 8 mm x 8 mm, the test environment temperature is 25°C, the test time is 30 ~ 60 seconds, and a standard piece is used for calibration before the test.

[0035] Further, the material of the auxiliary layer 6 includes a semiconductor material, and the semiconductor material is selected from at least one of a silicon element and a first metal oxide.

[0036] In the present embodiment, the first metal oxide is selected from one or more of doped or non-doped zinc oxide, barium oxide, aluminum oxide, nickel oxide, titanium oxide, tin oxide, tantalum oxide, zirconium oxide, nickel oxide, lithium titanium oxide, zinc aluminum oxide, zinc manganese oxide, zinc tin oxide, zinc lithium oxide, indium tin oxide.

[0037] Further, the thickness of the auxiliary layer 6 is 20-40 nm.

[0038] In the present embodiment, the thickness of the auxiliary layer 6 is 20-40 nm to ensure the electron transport efficiency; the thickness of the auxiliary layer 6 varies according to the requirement of the electron transport efficiency, and adjusting the thickness of the auxiliary layer 6 can balance the positive and negative carriers, which is not limited herein.

[0039] In some optional embodiments of the present embodiment, the thickness of the auxiliary layer 6 is any one of 20 nm, 22 nm, 24 nm, 26 nm, 28 nm, 30 nm, 32 nm, 34 nm, 36 nm, 38 nm, 40 nm, or a range between any two of them.

[0040] In some embodiments, the material of the electron functional layer 5 includes a second metal oxide doped with fluorine, and at least part of the second metal oxide doped with fluorine is distributed on the surface of the electron functional layer 5 close to the auxiliary layer 6.

[0041] Specifically, the active layer usually adopts quantum dot nanomaterials with core-shell structure. The organic surface ligand of the quantum dot nanoparticles and the fine core-shell structure inside the quantum dot nanoparticles result in that the annealing temperature of the active layer cannot be too high, the annealing temperature of the active layer limits the annealing temperature of the adjacent electron functional layer, the material of the electron functional layer is difficult to reach a better crystallization temperature, the internal structure of the electron functional layer is discontinuous, and the interface roughness is increased. In addition, the material of the electron functional layer generally includes a metal oxide, and the metal oxide prepared by the solution method usually has oxygen vacancy defects on the surface. Such defects can easily cause exciton quenching. In the present embodiment, the material of the electron functional layer 5 includes a second metal oxide doped with fluorine. The radius of fluorine ion is close to that of oxygen ion, and the fluorine ion can fill the oxygen vacancy position in the lattice of the second metal oxide, effectively reducing the defect state density of the electron functional layer 5, reducing the probability of electron capture, and thus improving the electron transport mobility of the electron functional layer 5.

[0042] In the present embodiment, at least part of the second metal oxide doped with fluorine is distributed on the surface of the electron functional layer 5 close to the auxiliary layer 6. The surface roughness and flatness of the electron functional layer 5 after fluorine ion passivation are improved, which is conducive to the more uniform distribution of the auxiliary layer 6 on the surface of the electron functional layer 5, reduces the interface contact resistance, and facilitates the combination of the electron functional layer 5 and the auxiliary layer 6.

[0043] In the present embodiment, the fluorine-doped second metal oxide is selected from at least one of zinc oxide, barium oxide, aluminum oxide, nickel oxide, titanium oxide, tin oxide, tantalum oxide, zirconium oxide, nickel oxide, titanium lithium oxide, zinc aluminum oxide, zinc manganese oxide, zinc tin oxide, zinc lithium oxide, indium tin oxide.

[0044] Further, the thickness of the electron functional layer 5 is 25 nm to 50 nm. Specifically, the thickness of the electron functional layer 5 can be any one of 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, 50 nm, or a range between any two of them.

[0045] Further, the doping concentration of fluorine in the electron functional layer is 0.8 wt% to 2.0 wt%, and specifically, the doping concentration of fluorine in the electron functional layer can be any one of 0.8 wt%, 1.0 wt%, 1.2 wt%, 1.4 wt%, 1.6 wt%, 1.8 wt%, 2.0 wt%, or a range between any two of them.

[0046] Further, the optoelectronic device further comprises a hole functional layer, which is located between the first electrode 1 and the active layer 4; wherein the hole functional layer comprises a hole transport layer 3 and a hole injection layer 2 stacked together, and the hole transport layer 3 is closer to the active layer 4 than the hole injection layer 2.

[0047] Further, the thickness of the first electrode 1 is 10 nm to 15 nm.

[0048] In some optional embodiments of the present embodiment, the thickness of the first electrode 1 is any one of 10 nm, 11 nm, 12 nm, 13 nm, 14 nm, 15 nm, or a range between any two of them.

[0049] Further, the thickness of the hole injection layer 2 is 20 nm to 100 nm.

[0050] In some optional embodiments of the present embodiment, the thickness of the hole injection layer 2 is any one of 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, 100 nm, or a range between any two of them.

[0051] Further, the thickness of the hole transport layer 3 is 20 nm to 100 nm.

[0052] In some optional embodiments of the present embodiment, the thickness of the hole transport layer 3 is any one of 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, 100 nm, or a range between any two of them.

[0053] Further, the thickness of the active layer 4 is 15 nm to 35 nm.

[0054] In some alternative embodiments of the present embodiment, the thickness of the active layer 4 is any one of 15 nm, 18 nm, 21 nm, 24 nm, 27 nm, 30 nm, 33 nm, 35 nm, or a range between any two of them.

[0055] Further, the thickness of the second electrode 7 is 15 nm to 40 nm.

[0056] In some alternative embodiments of the present embodiment, the thickness of the second electrode 7 is any one of 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, or a range between any two of them.

[0057] Further, the optoelectronic device further comprises a light extraction layer 8 and an encapsulation layer 9 which are sequentially stacked, and the light extraction layer 8 is arranged on the second electrode.

[0058] Further, the thickness of the light extraction layer 8 is 40 nm to 70 nm.

[0059] In some alternative embodiments of the present embodiment, the thickness of the light extraction layer 8 is any one of 40 nm, 50 nm, 60 nm, 70 nm, or a range between any two of them.

[0060] Further, the encapsulation layer 9 is an organic encapsulation layer, and the thickness of the organic encapsulation layer is 4 um to 16 um. In some alternative embodiments of the present embodiment, the thickness of the organic encapsulation layer is any one of 4 um, 6 um, 8 um, 10 um, 12 um, 14 um, 16 um, or a range between any two of them. The material of the organic encapsulation layer is selected from at least one of acrylic resin, epoxy resin, polyimide, and polyethylene.

[0061] In another implementation, the encapsulation layer 9 is an inorganic encapsulation layer, and the thickness of the inorganic encapsulation layer is 200 nm to 1000 nm. In some alternative embodiments of the present embodiment, the thickness of the inorganic encapsulation layer is any one of 200 nm, 400 nm, 600 nm, 800 nm, 1000 nm, or a range between any two of them. The material of the inorganic encapsulation layer is selected from at least one of silicon oxide, silicon nitride, and Al2O3, and other nitrides, non-metal oxides, and metal oxides which have water and oxygen blocking effects.

[0062] Further, the first electrode 1 and the second electrode 7 are each selected from one or more of a metal electrode, a silicon-carbon electrode, a doped or undoped metal oxide electrode, and a composite electrode; wherein the material of the metal electrode is selected from at least one of Al, Ag, Cu, Mo, Au, Ba, Ca, and Mg; the material of the silicon-carbon electrode is selected from at least one of silicon, graphite, carbon nanotube, graphene, and carbon fiber; the material of the doped or undoped metal oxide electrode is selected from at least one of ITO, FTO, ATO, AZO, GZO, IZO, MZO, and AMO; and the material of the composite electrode is selected from at least one of AZO / Ag / AZO, AZO / Al / AZO, ITO / Ag / ITO, ITO / Al / ITO, ZnO / Ag / ZnO, ZnO / Al / ZnO, TiO2 / Ag / TiO2, TiO2 / Al / TiO2, ZnS / Ag / ZnS, ZnS / Al / ZnS, TiO2 / Ag / TiO2, and TiO2 / Al / TiO2.

[0063] Further, the material of the active layer 4 includes at least one of a single-structure quantum dot and a core-shell structure quantum dot, the shell layer of the core-shell structure quantum dot includes one or more layers, and the material of the single-structure quantum dot, the core material of the core-shell structure quantum dot, and the shell layer material of the core-shell structure quantum dot are respectively selected from at least one of a II-VI compound, a IV-VI compound, a III-V compound, and a I-III-VI compound, wherein the II-VI compound includes one or more of CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, and HgZnSTe, the IV-VI compound includes one or more of SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, SnPbSSe, SnPbSeTe, and SnPbSTe, the III-V compound includes one or more of GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, and InAlPSb, and the I-III-VI compound includes at least one of CuInS2, CuInSe2, and AgInS2.

[0064] Further, the material of the hole transport layer 3 and the hole injection layer 2 independently comprises at least one of TFB, CuPc, PVK, Poly-TPD, PFB, DNTPD, TCATA, TCCA, CBP, TPD, NPB, NPD, PEDOT:PSS, TAPC, MCC, F4-TCNQ, HATCN, 4,4',4'-tris(N-3-methylphenyl-N phenylamino) triphenylamine, polyaniline, transition metal oxide, transition metal sulfide, transition metal tin, doped graphene, non-doped graphene and C60; the material of the hole transport layer 3 is selected from at least one of TFB, PVK, Poly-TPD, PFB, DNTPD, TCATA, TCCA, CBP, TPD, NPB, NPD, PEDOT:PSS and its derivatives, TAPC, MCC, C60.

[0065] Further, the material of the light extraction layer 8 comprises at least one of SnO2, TiO2, ZrO2, indium zinc oxide, HfO2and ZnO2.

[0066] The application also provides a method for manufacturing the optoelectronic device of any one of the above examples, as shown in the following steps. Figure 2 As shown in the following steps:

[0067] Step S11, providing a first pre-device, the first pre-device comprising a first electrode, an active layer and an electronic functional layer which are sequentially stacked;

[0068] Step S12, forming an auxiliary layer on the electronic functional layer;

[0069] Step S13, forming a second electrode on the side of the auxiliary layer away from the electronic functional layer to obtain the optoelectronic device;

[0070] Alternatively,

[0071] Step S11, providing a second pre-device, the second pre-device comprising a second electrode and an electronic functional layer which are sequentially stacked;

[0072] Step S12, forming an auxiliary layer on the electronic functional layer;

[0073] Step S13, sequentially forming an active layer and a first electrode on the side of the auxiliary layer away from the electronic functional layer to obtain the optoelectronic device;

[0074] Wherein, the material of the auxiliary layer comprises a semiconductor material, and the electron mobility of the auxiliary layer is less than the electron mobility of the electronic functional layer.

[0075] In an embodiment, the electron mobility of the electronic functional layer is 10 -2 ~ 10-1 cm 2 / (V*S).

[0076] In an embodiment, the electron mobility of the auxiliary layer is 10 -3 ~10 -2 cm 2 / (V*S).

[0077] The present application increases the injection barrier of the electron from the second electrode to the electron functional layer by preparing an auxiliary layer on the electron functional layer, and the electron mobility of the auxiliary layer is less than that of the electron functional layer, reduces the electron transport efficiency from the electron functional layer to the active layer, effectively improves the problem that the electron injection and transport rate is much greater than the hole injection and transport rate, realizes the balance of electron and hole injection of the active layer, and thus improves the light-emitting efficiency and service life of the optoelectronic device.

[0078] In an embodiment, the following step is further included before step S12:

[0079] A fluorine-containing gas is provided to the first pre-device or the second pre-device, and a plasma surface treatment method is used to form a fluorine plasma from the fluorine-containing gas and deposit it on the surface of the electron functional layer away from the active layer, so as to form a fluorine-doped second metal oxide on the surface of the electron functional layer.

[0080] In an embodiment, a fluorine plasma is generated in a chemical vapor deposition system by using a plasma-enhanced chemical vapor deposition method through fluorine element plasma bombardment to perform fluorine doping treatment on the surface of the electron functional layer. The fluorine ions in the fluorine plasma can fill the oxygen vacancy positions in the metal oxide lattice, effectively reduce the defect state density of the electron functional layer, reduce the probability of electron capture, and thus improve the electron transport mobility of the electron functional layer. In addition, the surface roughness and flatness of the electron functional layer after fluorine ion passivation are improved, which is conducive to the uniform distribution of the auxiliary layer on the surface of the electron functional layer, reduces the interface contact resistance, and facilitates the combination of the electron functional layer and the auxiliary layer.

[0081] The gas atmosphere for realizing the fluorine ion doping treatment by using the plasma-enhanced chemical vapor deposition method includes any one of tetrafluoromethane, trifluoromethane, nitrogen trifluoride, and nitrogen tetrafluoride, the working power is 1400W-5000W, and specifically, the working power can be any one of 1400W, 2400W, 3400W, 4400W, 5000W, or a range between any two of them; the treatment time is 1 second-20 seconds, and specifically, the treatment time can be any one of 1 second, 4 seconds, 7 seconds, 11 seconds, 15 seconds, 18 seconds, 20 seconds, or a range between any two of them.

[0082] In an embodiment, the step S12 of forming the auxiliary layer on the electronic functional layer specifically comprises: placing the first pre-device or the second pre-device into a silicon-containing atmosphere to perform a first reaction, so as to deposit the auxiliary layer on the surface of the electronic functional layer, and the material of the auxiliary layer comprises silicon element. The silicon-containing atmosphere comprises silane and hydrogen, and the silane comprises at least one of monosilane and disilane.

[0083] In the embodiment, the auxiliary layer is deposited on the surface of the fluorine-doped second metal oxide by a chemical vapor deposition method, and the material of the auxiliary layer comprises semiconductor silicon element. Specifically, the silane and the hydrogen are introduced into a chemical vapor deposition furnace to deposit the auxiliary layer with a thickness of 20-40 nm on the electronic functional layer, the flow rate of the silane is 300-800 seem, specifically, the flow rate of the silane can be any one of 300 seem, 400 seem, 500 seem, 600 seem, 700 seem and 800 seem or a range between any two of them; the flow rate of the hydrogen is 1000-3000 seem, specifically, the flow rate of the hydrogen can be any one of 1000 seem, 1500 seem, 2000 seem, 2500 seem and 3000 seem or a range between any two of them; the deposition time is 12-24 seconds, specifically, the deposition time can be any one of 12 seconds, 14 seconds, 16 seconds, 18 seconds, 20 seconds, 22 seconds and 24 seconds or a range between any two of them; the deposition temperature is 85-100℃, specifically, the deposition temperature can be any one of 85℃, 90℃, 95℃ and 100℃ or a range between any two of them; the deposition pressure is 0.3-0.6 Pa, specifically, the deposition pressure can be any one of 0.3 Pa, 0.4 Pa, 0.5 Pa and 0.6 Pa or a range between any two of them; and the deposition power is 1400-4000 W, specifically, the deposition power can be any one of 1400 W, 1800 W, 2000 W, 2400 W, 2800 W, 3000 W, 3400 W, 3800 W and 4000 W or a range between any two of them.

[0084] In another embodiment, the auxiliary layer is deposited on the surface of the electronic functional layer of the first pre-device or the second pre-device by a sputtering method. The first metal oxide is selected from one or more of doped or undoped zinc oxide, barium oxide, aluminum oxide, nickel oxide, titanium oxide, tin oxide, tantalum oxide, zirconium oxide, nickel oxide, lithium titanium oxide, zinc aluminum oxide, zinc manganese oxide, zinc tin oxide and zinc lithium oxide.

[0085] Further, the process parameters of the sputtering method are as follows: the main component of the target material is metal and oxygen, an argon atmosphere is adopted, the deposition pressure is 0.2 Pa to 0.4 Pa, specifically, the deposition pressure can be any one of 0.2 Pa, 0.3 Pa, 0.4 Pa or a range between any two of them; the sputtering power is 2000 W to 4000 W, specifically, the sputtering power can be any one of 2000 W, 2500 W, 3000 W, 3500 W, 4000 W or a range between any two of them; the deposition time is 180 seconds to 360 seconds, specifically, the deposition time can be any one of 180 seconds, 220 seconds, 260 seconds, 300 seconds, 330 seconds, 360 seconds or a range between any two of them.

[0086] In some embodiments, the method for manufacturing the optoelectronic device further comprises the following steps:

[0087] A hole injection layer is formed between the first electrode and the active layer, and the thickness of the hole injection layer is 20 nm to 100 nm. Specifically, the thickness of the hole injection layer can be any one of 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, 100 nm or a range between any two of them.

[0088] In some embodiments, the method for manufacturing the optoelectronic device further comprises the following steps:

[0089] A hole transport layer is formed between the hole injection layer and the active layer, and the thickness of the hole transport layer is 20 nm to 100 nm. Specifically, the thickness of the hole transport layer can be any one of 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, 100 nm or a range between any two of them.

[0090] In some embodiments, the method for manufacturing the optoelectronic device further comprises the following steps:

[0091] A light extraction layer is formed on the side of the second electrode away from the auxiliary layer, and the thickness of the light extraction layer is 40 nm to 70 nm. Specifically, the thickness of the light extraction layer can be any one of 40 nm, 50 nm, 60 nm, 70 nm or a range between any two of them.

[0092] The materials of the above-mentioned first electrode, hole injection layer, hole transport layer, active layer, electron functional layer, auxiliary layer, light extraction layer and other functional layers are as described above, and will not be repeated here.

[0093] The preparation method of the first electrode, the hole injection layer, the hole transport layer, the active layer, the electron functional layer, the light extraction layer, and the like can adopt conventional preparation methods in the art, including: a solution method or an evaporation method; optionally, the solution method includes but is not limited to one or more of a spin coating method, a printing method, a blade coating method, an immersion pulling method, a soaking method, a spraying method, a roll coating method, a casting method, a slot coating method, and a strip coating method; further, the printing method includes but is not limited to inkjet printing.

[0094] The application also provides a display device comprising the optoelectronic device as described above or prepared by the method as described above.

[0095] In some embodiments, the display device can be any electronic product with a display function, including but not limited to a smart phone, a tablet computer, a notebook computer, a digital camera, a digital camcorder, a smart wearable device, a smart weighing electronic scale, a vehicle-mounted display, a television, or an electronic book reader, wherein the smart wearable device can be, for example, a smart bracelet, a smart watch, or a virtual reality.

[0096] The above solutions are further described below in combination with specific examples. Preferred embodiments of the application are described in detail as follows:

[0097] Embodiment 1:

[0098] The application provides a preparation method of an optoelectronic device, and the preparation method is as follows:

[0099] Step 1: providing a first electrode, the thickness of the first electrode being 10 nm;

[0100] Step 2: forming a hole injection layer on the first electrode by an inkjet printing method, the thickness of the hole injection layer being 80 nm;

[0101] Step 3: forming a hole transport layer on the hole injection layer by the inkjet printing method, the thickness of the hole transport layer being 20 nm;

[0102] Step 4: forming a quantum dot light-emitting layer on the hole transport layer by the inkjet printing method, the thickness of the quantum dot light-emitting layer being 30 nm;

[0103] Step 5: forming an electron functional layer on the quantum dot light-emitting layer by the inkjet printing method, the material of the electron functional layer being zinc oxide, and the thickness of the electron functional layer being 30 nm;

[0104] Step 6: performing fluorine doping treatment on the surface of the electron functional layer by a plasma-enhanced chemical vapor deposition method to form fluorine-doped zinc oxide on the surface of the electron functional layer, wherein the gas introduced is nitrogen trifluoride gas, the power is 1400 W, and the processing time is 15 seconds;

[0105] Step 7: A semiconductor silicon layer is prepared on the electronic functional layer with fluorine-doped zinc oxide on the surface by chemical vapor deposition method, the gas introduced is silane and hydrogen, the power is 1400W, the gas pressure is 0.4Pa, the temperature is 85℃, the flow rate of SiH4 is 400sccm, the flow rate of H2 is 1500sccm, the deposition time is 18 seconds, and the thickness of the semiconductor silicon layer is 30nm;

[0106] Step 8: A second electrode is prepared on the semiconductor silicon layer by evaporation method, and the thickness of the second electrode is 35nm;

[0107] Step 9: A light extraction layer is formed on the second cathode by evaporation method, and the thickness of the light extraction layer is 60nm;

[0108] Step 10: An encapsulation layer is formed on the light extraction layer.

[0109] Example 2

[0110] The difference from Example 1 is that:

[0111] The material of the electronic functional layer in Step 5 is indium tin oxide;

[0112] The corresponding change in Step 6 is that the surface of the electronic functional layer is treated by plasma-enhanced chemical vapor deposition to form fluorine-doped indium tin oxide on the surface of the electronic functional layer;

[0113] The corresponding change in Step 7 is that a semiconductor silicon layer is prepared on the electronic functional layer with fluorine-doped indium tin oxide on the surface by chemical vapor deposition method.

[0114] Example 3

[0115] The difference from Example 1 is that:

[0116] Step 6 is not performed;

[0117] The thickness of the semiconductor silicon layer in Step 7 is 20nm;

[0118] The corresponding change in Step 7 is that a semiconductor silicon layer is prepared on the electronic functional layer by chemical vapor deposition method.

[0119] Example 4

[0120] The difference from Example 1 is that:

[0121] Step 6 is not performed;

[0122] The thickness of the semiconductor silicon layer in Step 7 is 60nm;

[0123] The corresponding change in Step 7 is that a semiconductor silicon layer is prepared on the electronic functional layer by chemical vapor deposition method.

[0124] Example 5

[0125] The difference from Example 1 is that:

[0126] The auxiliary layer in Step 7 is an indium tin oxide semiconductor layer;

[0127] The corresponding change in Step 7 is that an indium tin oxide semiconductor layer is prepared on the electronic functional layer containing fluorine-doped zinc oxide on the surface by a vacuum sputtering method, and the thickness of the indium tin oxide semiconductor layer is 30 nm.

[0128] Example 6

[0129] The difference from Example 1 is that:

[0130] The auxiliary layer in Step 7 is a zinc oxide semiconductor layer;

[0131] The corresponding change in Step 7 is that a zinc oxide semiconductor layer is prepared on the electronic functional layer containing fluorine-doped zinc oxide on the surface by a vacuum sputtering method, and the thickness of the zinc oxide semiconductor layer is 30 nm.

[0132] Example 7

[0133] The difference from Example 1 is that:

[0134] The gas introduced in Step 6 is tetrafluoromethane;

[0135] The corresponding change in Step 6 is that the surface of the electronic functional layer is treated by fluorine doping using a plasma-enhanced chemical vapor deposition method to form fluorine-doped zinc oxide on the surface of the electronic functional layer, wherein the gas introduced is tetrafluoromethane gas, the power is 1400W, and the treatment time is 15 seconds.

[0136] Comparative Example 1

[0137] The difference from Example 1 is that:

[0138] Steps 6 and 7 are not performed;

[0139] The corresponding change in Step 8 is that a second electrode is prepared on the electronic functional layer by an evaporation method.

[0140] Comparative Example 2

[0141] The difference from Example 1 is that:

[0142] Step 7 is not performed;

[0143] The corresponding change in Step 8 is that a second electrode is prepared on the electronic functional layer containing fluorine-doped zinc oxide on the surface by an evaporation method.

[0144] Comparative Example 3

[0145] The difference from Example 1 is that:

[0146] The operation of Step 6 is not performed.

[0147] The thickness of the semiconductor silicon layer of Step 7 is 10 nm.

[0148] The corresponding change of Step 7 is that the semiconductor silicon layer is prepared on the electronic functional layer by chemical vapor deposition.

[0149] Comparative Example 4

[0150] The difference from Example 1 is that:

[0151] The operation of Step 6 is not performed.

[0152] The corresponding change of Step 7 is that the semiconductor silicon layer is prepared on the electronic functional layer by chemical vapor deposition.

[0153] The photoelectric devices prepared in Examples 1-7 and Comparative Examples 1-4 are subjected to current efficiency test and service life test.

[0154] The test method of current efficiency is as follows: the light-emitting area is set to 2 mm x 2 mm = 4 mm 2 , the luminance value of the light-emitting device in the driving voltage range of 0 V to 8 V is collected intermittently, the initial voltage value of luminance collection is 0.5 V, the collection is performed every 0.2 V, and the current efficiency of the light-emitting device under the collection condition is obtained by dividing the luminance value collected each time by the corresponding current density.

[0155] The test method of service life is as follows: under the driving of constant current (2 mA), the electroluminescent service life of each light-emitting device is analyzed by using a 128-channel QLED service life test system, the time (T95, h) required for each light-emitting device to decay from maximum brightness to 95% is recorded, and the time (T95@1000nit, h) required for the brightness of each light-emitting device to decay from 100% to 95% under the brightness of 1000 nit is calculated by using the decay fitting formula.

[0156] The test results are shown in Table 1.

[0157] Table 1

[0158]

[0159]

[0160] As shown in Table 1, compared with Comparative Examples 1 and 2, the current efficiency and the lifetime of the devices of Examples 1-7 are significantly increased by adding the auxiliary layer between the electron functional layer and the second electrode. It can be seen that the auxiliary layer provided in the photoelectric device of the present application can effectively improve the luminous efficiency and the service life of the photoelectric device. The reason can be that the electron mobility of the auxiliary layer of the photoelectric device of Examples 1-7 is less than the electron mobility of the electron functional layer, and the auxiliary layer can control the migration amount and migration rate of the electrons transmitted to the electron functional layer by the second electrode, thereby improving the injection balance of holes and electrons in the active layer, and improving the luminous efficiency and the service life of the photoelectric device.

[0161] According to the test results of photoelectric device Examples 1, 2, 5, 6, 7 and photoelectric device Comparative Example 4, it can be known that by performing fluorine doping treatment on the surface of the electron functional layer close to the side of the auxiliary layer, the electron functional layer body defect state density can be effectively reduced, and the probability of electron capture can be reduced. At the same time, the surface roughness and flatness of the electron functional layer after fluorine ion passivation are improved, the interface contact resistance between the electron functional layer and the auxiliary layer is reduced, the combination of the electron functional layer and the auxiliary layer is facilitated, and the luminous efficiency and the service life of the photoelectric device are improved.

[0162] According to the test results of photoelectric device Examples 3, 4 and photoelectric device Comparative Example 3, it can be known that by appropriately setting the thickness of the auxiliary layer, the injection balance of holes and electrons in the active layer can be further ensured, and the luminous efficiency and the service life of the photoelectric device are improved.

[0163] Obviously, the above-described embodiments are only some embodiments of the present application, not all embodiments, and the preferred embodiments of the present application are given in the drawings, but do not limit the patent scope of the present application. The present application can be implemented in many different forms, and conversely, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments, or make equivalent replacements to some technical features. Any equivalent structure made by using the contents of the specification and drawings, directly or indirectly applied to other related technical fields, is also within the scope of the patent protection of the present application.

Claims

1. An optoelectronic device, characterized in that, The optoelectronic device includes a first electrode, an active layer, an electronic functional layer, an auxiliary layer, and a second electrode, which are stacked sequentially. The auxiliary layer is made of semiconductor material, and the electron mobility of the auxiliary layer is less than that of the electronic functional layer.

2. The optoelectronic device according to claim 1, characterized in that, The electron mobility of the electronic functional layer is 10. -2 ~10 -1 cm 2 / (V*S); and / or The electron mobility of the auxiliary layer is 10. -3 ~10 -2 cm 2 / (V*S).

3. The optoelectronic device according to claim 1, characterized in that, The semiconductor material is selected from at least one of elemental silicon and a first metal oxide; and / or The material of the electronic functional layer includes a fluorine-doped second metal oxide.

4. The optoelectronic device according to claim 3, characterized in that, The material of the electronic functional layer further includes the second metal oxide, and at least a portion of the fluorine-doped second metal oxide is distributed on the surface of the electronic functional layer near the auxiliary layer; and / or The fluorine doping concentration in the electronic functional layer is 0.8 wt% to 2.0 wt%; and / or The first metal oxide and the second metal oxide are each independently selected from one or more of the following: doped or undoped zinc oxide, barium oxide, aluminum oxide, nickel oxide, titanium oxide, tin oxide, tantalum oxide, zirconium oxide, nickel oxide, lithium titanium oxide, zinc aluminum oxide, zinc manganese oxide, zinc tin oxide, zinc lithium oxide, and indium tin oxide.

5. The optoelectronic device according to any one of claims 1 to 4, characterized in that, The thickness of the electronic functional layer is 25nm to 50nm; and / or The thickness of the auxiliary layer is 20nm to 40nm.

6. The optoelectronic device according to any one of claims 1 to 4, characterized in that, The first electrode and the second electrode are each selected from one or more of the following: a metal electrode, a silicon-carbon electrode, a doped or undoped metal oxide electrode, and a composite electrode; wherein, the material of the metal electrode is selected from at least one of Al, Ag, Cu, Mo, Au, Ba, Ca, and Mg; the material of the silicon-carbon electrode is selected from at least one of silicon, graphite, carbon nanotubes, graphene, and carbon fiber; the material of the doped or undoped metal oxide electrode is selected from at least one of ITO, FTO, ATO, AZO, GZO, IZO, MZO, and AMO; the material of the composite electrode is selected from at least one of AZO / Ag / AZO, AZO / Al / AZO, ITO / Ag / ITO, ITO / Al / ITO, ZnO / Ag / ZnO, ZnO / Al / ZnO, TiO2 / Ag / TiO2, TiO2 / Al / TiO2, ZnS / Ag / ZnS, ZnS / Al / ZnS, TiO2 / Ag / TiO2, and TiO2 / Al / TiO2; and / or The active layer material comprises at least one of single-structure quantum dots and core-shell structure quantum dots, wherein the shell of the core-shell structure quantum dots comprises one or more layers; the material of the single-structure quantum dots, the core material of the core-shell structure quantum dots, and the shell material of the core-shell structure quantum dots are respectively selected from at least one of group II-VI compounds, group IV-VI compounds, group III-V compounds, and group I-III-VI compounds, wherein group I-VI compounds include CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, CdZn One or more of the following compounds: SeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, and HgZnSTe; and group IV-VI compounds including SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, and S. One or more of nPbSSe, SnPbSeTe, and SnPbSTe; III-V compounds including one or more of GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, and InAlPSb; I-III-VI compounds including at least one of CuInS2, CuInSe2, and AgInS2; and / or The optoelectronic device further includes a hole functional layer located between the first electrode and the active layer; wherein the hole functional layer includes a stacked hole transport layer and a hole injection layer, and the hole transport layer is closer to the active layer than the hole injection layer. The materials of the hole transport layer and the hole injection layer independently include at least one of TFB, CuPc, PVK, Poly-TPD, PFB, DNTPD, TCATA, TCCA, CBP, TPD, NPB, NPD, PEDOT:PSS, T·APC, MCC, F4-TCNQ, HATCN, 4,4',4'-tris(N-3-methylphenyl-N-phenylamino)triphenylamine, polyaniline, transition metal oxides, transition metal sulfides, transition metal tin compounds, doped graphene, undoped graphene, and C60; the material of the hole transport layer is selected from at least one of TFB, PVK, Poly-TPD, PFB, DNTPD, TCATA, TCCA, CBP, TPD, NPB, NPD, PEDOT:PSS and its derivatives, TAPC, MCC, and C60.

7. A method for fabricating an optoelectronic device, characterized in that, The preparation steps include the following: A first prefabricated device is provided, the first prefabricated device comprising a first electrode, an active layer and an electronic functional layer stacked sequentially; An auxiliary layer is formed on the electronic functional layer; A second electrode is formed on the side of the auxiliary layer away from the electronic functional layer to obtain the optoelectronic device; or, A second prefabricated device is provided, the second prefabricated device comprising a second electrode and an electronic functional layer stacked sequentially; An auxiliary layer is formed on the electronic functional layer; An active layer and a first electrode are sequentially formed on the side of the auxiliary layer away from the electronic functional layer to obtain the optoelectronic device; The auxiliary layer is made of semiconductor material, and the electron mobility of the auxiliary layer is less than that of the electronic functional layer.

8. The preparation method according to claim 7, characterized in that, The electron mobility of the electronic functional layer is 10. -2 ~10 -1 cm 2 / (V*S); and / or The electron mobility of the auxiliary layer is 10. -3 ~10 -2 cm 2 / (V*S); and / or The material of the electronic functional layer includes the second metal oxide, and the step of forming an auxiliary layer on the electronic functional layer is further included before the step of forming an auxiliary layer on the electronic functional layer: Fluorine plasma is deposited onto the surface of the electronic functional layer away from the active layer to form a fluorine-doped second metal oxide.

9. The preparation method according to claim 8, characterized in that, The step of depositing fluorine plasma onto the surface of the electronic functional layer away from the active layer includes: Fluorine-containing gas is supplied to the first preform or the second preform, and the fluorine-containing gas is used to form fluorine plasma and deposited onto the surface of the electronic functional layer away from the active layer using a plasma surface treatment method. The fluorine-containing gas includes at least one of tetrafluoromethane, trifluoromethane, nitrogen trifluoride, and nitrogen tetrafluoride; and / or The plasma surface treatment operates at a power of 1400W to 5000W and takes 1 to 20 seconds.

10. The preparation method according to claim 7, characterized in that, The step of forming an auxiliary layer on the electronic functional layer includes: Silane and hydrogen are provided to the first preform or the second preform, and the silane and hydrogen undergo a first reaction to deposit the auxiliary layer on the surface of the electronic functional layer; Alternatively, the auxiliary layer may be formed by depositing a first metal oxide on the surface of the electronic functional layer of the first prefabricated device or the second prefabricated device using a sputtering method.

11. The preparation method according to claim 10, characterized in that, The silane includes at least one of methylsilane and ethylsilane; and / or The flow rate of the silane is 300 sccm to 800 sccm, and / or the flow rate of the hydrogen is 1000 sccm to 3000 sccm; and / or The first reaction time is 12 to 24 seconds, and / or the temperature is 85°C to 100°C, the deposition pressure is 0.3 Pa to 0.6 Pa, and / or the deposition power is 1400 W to 4000 W; and / or In the sputtering method, the deposition gas pressure is 0.2 Pa to 0.4 Pa, and / or the sputtering power is 2000 W to 4000 W, and / or the deposition time is 180 seconds to 360 seconds.

12. A display device comprising an optoelectronic device as described in any one of claims 1 to 6 or an optoelectronic device prepared by the method described in any one of claims 7 to 11.

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