CN113130824A - Quantum dot light-emitting diode and preparation method thereof - Google Patents

Quantum dot light-emitting diode and preparation method thereof Download PDF

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CN113130824A
CN113130824A CN201911399797.6A CN201911399797A CN113130824A CN 113130824 A CN113130824 A CN 113130824A CN 201911399797 A CN201911399797 A CN 201911399797A CN 113130824 A CN113130824 A CN 113130824A
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quantum dot
layer
carbon quantum
carbon
hole transport
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CN113130824B (en
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黄盼宁
卢子哲
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TCL Research America Inc
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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]
    • H10K50/14—Carrier transporting layers
    • H10K50/15—Hole transporting layers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y30/00—Nanotechnology for materials or surface science, e.g. nanocomposites
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y40/00—Manufacture or treatment of nanostructures
    • 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
    • H10K50/00—Organic light-emitting devices
    • H10K50/10—OLEDs or polymer light-emitting diodes [PLED]
    • H10K50/14—Carrier transporting layers
    • H10K50/15—Hole transporting layers
    • H10K50/156—Hole transporting layers comprising a multilayered structure
    • 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
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K2102/00—Constructional details relating to the organic devices covered by this subclass

Abstract

The invention belongs to the technical field of display devices, and particularly relates to a quantum dot light-emitting diode which comprises a hole transport layer, a quantum dot light-emitting layer and a first carbon quantum dot layer, wherein the first carbon quantum dot layer is arranged between the hole transport layer and the quantum dot light-emitting layer, and comprises a plurality of first carbon quantum dots. The quantum dot light-emitting diode provided by the invention has the advantages of good charge transmission performance, high conductivity and stable performance.

Description

Quantum dot light-emitting diode and preparation method thereof
Technical Field
The invention belongs to the technical field of display devices, and particularly relates to a quantum dot light-emitting diode and a preparation method thereof.
Background
The Quantum Dots (QDs) have the advantages of adjustable luminescence wavelength, narrow peak width, high luminescence efficiency, long service life, high thermal stability, excellent solution-soluble processability and the like due to the obvious quantum dot confinement effect, and have wide application prospects in the fields of novel display and illumination, solar cells, biomarkers and the like. In recent years, quantum dot luminescent materials play a great role in the fields of LED illumination, liquid crystal display and the like, and quantum dots replace traditional fluorescent powder, so that the color gamut of LED and liquid crystal display is effectively improved. Recently, quantum dot light emitting diodes (QLEDs) using quantum dot light emitting materials as light emitting layers have a wide application prospect in the fields of solid state lighting, flat panel display, etc., have received extensive attention from the academic and industrial fields, have the advantages of wide color gamut range, saturated color, high color purity, low preparation cost, etc., and become a next-generation novel display with great potential.
The quantum dot light emitting diode structure is a typical 'sandwich' structure, and because the charge mobility of a hole transport material is generally lower than that of an electron transport layer material, the device often causes imbalance of electron and hole injection during operation, and a large amount of carriers are accumulated between the quantum dot and the hole transport layer interface. Too many carriers can easily cause non-radiative recombination and even quench luminescence, which greatly limits the great improvement of the QLED device performance. At present, the material of the hole transport layer generally adopts poly (3, 4-ethylenedioxythiophene): polystyrene sulfonate (PEDOT: PSS) conductive polymer, and the PEDOT: PSS has many advantages of higher conductivity, narrow energy band width, high light transmittance, high stability, solution-soluble processability, environmental friendliness and the like, and is a conductive polymer material which is researched more and widely applied at the present stage, and is also commonly used as a hole transport material for preparing a QLED device. However, the conductivity of the PEDOT/PSS hole material still needs to be further improved, and the acidity of the PEDOT/PSS hole material is corrosive to an electrode and affects the stability of a device because PSS contains an amphoteric functional group and sulfonic acid is strong acid.
Disclosure of Invention
The invention aims to provide a quantum dot light-emitting diode, aiming at solving the technical problems that the conductivity of a hole transmission layer in the quantum dot light-emitting diode is still low, and the stability of a device is influenced by acid corrosion of electrodes of hole materials such as PEDOT (PEDOT-patterned sapphire substrate), PSS (patterned sapphire substrate) and the like to a certain extent.
The invention also aims to provide a preparation method of the quantum dot light-emitting diode.
In order to achieve the purpose of the invention, the technical scheme adopted by the invention is as follows:
a quantum dot light-emitting diode comprises a hole transport layer, a quantum dot light-emitting layer and a first carbon quantum dot layer, wherein the first carbon quantum dot layer is arranged between the hole transport layer and the quantum dot light-emitting layer, and the first carbon quantum dot layer comprises a plurality of first carbon quantum dots.
Correspondingly, the preparation method of the quantum dot light-emitting diode comprises the following steps:
providing a hole transport layer, and depositing first carbon quantum dots on the hole transport layer to form a first carbon quantum dot layer;
depositing a quantum dot material on the surface of the other side, far away from the hole transport layer, of the first carbon quantum dot layer to form a quantum dot light-emitting layer;
alternatively, the first and second electrodes may be,
providing a quantum dot light-emitting layer, and depositing a first carbon quantum dot on the quantum dot light-emitting layer to form a first carbon quantum dot layer;
and depositing a hole transport material on the surface of the other side, far away from the quantum dot light emitting layer, of the first carbon quantum dot layer to form a hole transport layer.
The quantum dot light-emitting diode comprises a hole transmission layer, a quantum dot light-emitting layer and a first carbon quantum dot layer, wherein the first carbon quantum dot layer is arranged between the hole transmission layer and the quantum dot light-emitting layer and comprises a plurality of carbon quantum dots; on the other hand, light emitted by the quantum dot light-emitting layer close to the hole transport layer can be effectively absorbed by the middle second carbon quantum dot layer, and the light energy is converted into energy required by carrier transmission through photoelectric conversion, so that the transmission capability of the hole transport layer can be effectively improved. And the nano-scale carbon quantum dot material can be well connected between the hole transport materials to form an interpenetrating conductive network structure, and the isolated hole transport materials are used as a direct charge transport bridge to be connected and communicated to form a high-efficiency conductive layer, so that the conductivity of the hole transport layer is further improved.
The preparation method of the quantum dot light-emitting diode provided by the invention can prepare all functional layers from one side containing a hole transport layer, and sequentially deposit a first carbon quantum dot layer, a quantum dot light-emitting layer and other functional layers on the hole transport layer; the preparation method is simple, is suitable for preparing the positive type structure quantum dot light-emitting diode and the inverse type structure quantum dot light-emitting diode, is flexible to operate and wide in adaptability, and can meet different application requirements.
Drawings
Fig. 1 is a first schematic flow chart of a method for manufacturing a quantum dot light-emitting diode according to an embodiment of the present invention.
Fig. 2 is a second schematic flow chart of a method for manufacturing a quantum dot light-emitting diode according to an embodiment of the present invention.
Fig. 3 is a schematic structural diagram of a quantum dot light emitting diode according to an embodiment of the present invention.
Detailed Description
In order to make the purpose, technical solution and technical effect of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention is clearly and completely described, and it is obvious that the described embodiments are a part of the embodiments of the present invention, but not all embodiments. All other embodiments obtained by a person of ordinary skill in the art without any inventive step in connection with the embodiments of the present invention shall fall within the scope of protection of the present invention.
In the description of the present invention, it is to be understood that the terms "first", "second" and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implying any number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.
The weight of the related components mentioned in the description of the embodiments of the present invention may not only refer to the specific content of each component, but also represent the proportional relationship of the weight among the components, and therefore, the content of the related components is scaled up or down within the scope disclosed in the description of the embodiments of the present invention as long as it is in accordance with the description of the embodiments of the present invention. Specifically, the weight described in the description of the embodiment of the present invention may be a unit of mass known in the chemical industry field, such as μ g, mg, g, and kg.
As shown in fig. 3, an embodiment of the present invention provides a quantum dot light emitting diode, which includes a hole transport layer, a quantum dot light emitting layer, and a first carbon quantum dot layer, where the first carbon quantum dot layer is disposed between the hole transport layer and the quantum dot light emitting layer, and the first carbon quantum dot layer includes a plurality of first carbon quantum dots.
The quantum dot light-emitting diode provided by the embodiment of the invention comprises a hole transmission layer, a quantum dot light-emitting layer and a first carbon quantum dot layer, wherein the first carbon quantum dot layer is arranged between the hole transmission layer and the quantum dot light-emitting layer, the first carbon quantum dot layer comprises a plurality of first carbon quantum dots, and the carbon quantum dots have the characteristics of excellent carrier transmission performance, higher mobility, chemical stability, better light permeability and the like; on the other hand, light emitted by the quantum dot light-emitting layer close to the hole transport layer can be effectively absorbed by the middle second carbon quantum dot layer, and the light energy is converted into energy required by carrier transmission through photoelectric conversion, so that the transmission capability of the hole transport layer can be effectively improved. And the nano-scale carbon quantum dot material can be well connected between the hole transport materials to form an interpenetrating conductive network structure, and the isolated hole transport materials are used as a direct charge transport bridge to be connected and communicated to form a high-efficiency conductive layer, so that the conductivity of the hole transport layer is further improved.
In some embodiments, the quantum dot light emitting diode further comprises a second carbon quantum dot layer disposed between the anode and the hole transport layer and an anode, the second carbon quantum dot layer comprising a number of second carbon quantum dots. According to the embodiment of the invention, the second carbon quantum dot layer is arranged between the anode of the quantum dot light-emitting diode and the hole transport layer, so that the charge transport capability between the electrode and the hole transport layer can be improved, the corrosion of PEDOT, PSS and other hole transport layer materials to the electrode can be avoided, and the stability of the device is improved. It should be noted that the first carbon quantum dots may be quantum dots having the same size or shape as the second carbon quantum dots, or quantum dots having different sizes or shapes.
In some embodiments, amino-functionalized carbon quantum dots are included in the first and/or second carbon quantum dot layers. In the embodiment of the invention, the first carbon quantum dot layer or the second carbon quantum dot layer or both of the first carbon quantum dot layer and the second carbon quantum dot layer comprise carbon quantum dots with amino functionalization, and the carbon quantum dots are spherical or spherical-like with the size smaller than 10 nanometers and have the characteristics of small particles, high mobility, excellent chemical stability, high light transmittance and the like. And the carbon quantum dots also have larger sp2The conjugated carbon plane structure and a large number of functional groups modified on the surface have strong absorption in a short wave region (230-320 nm), the absorption end can extend to a visible light region, and a certain intermolecular interaction force (pi-pi interaction) can be formed with the hole transport layer, so that the conductivity of the composite material can be increased. The carbon quantum dots with amino functionalization have high fluorescence intensity and high fluorescence quantum yield, are not influenced by the color of non-fluorescent dye, and can better convert absorbed light energyThe energy required for carrier transport, and the amino active group in the carbon quantum dot has better combination tightness with the electrode and the hole transport layer material.
In some examples, the first carbon quantum dot is an amino-functionalized carbon quantum dot. In some examples, the second carbon quantum dot is an amino-functionalized carbon quantum dot.
In some embodiments, the thickness of the second carbon quantum dot layer is 20-40 nm, and the second carbon quantum dot layer with the thickness can effectively prevent the corrosion of hole transport materials such as PEDOT, PSS and the like to the electrode, ensure that the electrode is not corroded, and ensure that the contact surface is relatively flat and does not form a large contact barrier to influence the transmission of carriers.
In some embodiments, the thickness of the first carbon quantum layer is 20-40 nm, the flatness of the first carbon quantum dot layer film layer with the thickness is good, a large contact barrier cannot be formed to influence the transmission of carriers, light emitted by the quantum dot light-emitting layer close to one side of the hole transmission layer can be absorbed and converted into energy required by the transmission of the carriers, and the transmission capability of the hole transmission layer is effectively improved.
In some embodiments, the material of the hole transport layer comprises PEDOT: PSS. The hole transport layer material of the quantum dot light-emitting diode provided by the embodiment of the invention adopts PEDOT PSS which has the characteristics of high transparency, solution processing preparation, good thermal stability, easiness in deposition, low surface roughness, low cost and the like, has very good physical flexibility and good stability under the action of external force, and the transparent conductive film of the PEDOT PSS still keeps higher electrical properties after a tensile test, so that the quantum dot light-emitting diode provided by the embodiment of the invention is very suitable for being used as a flexible device, and has wider application prospect. And the PEDOT and PSS have the characteristics of high work function, excellent light transmittance, good film-forming property and the like, and can well improve the photoelectric conversion efficiency of the device when used as a hole transport layer. The second carbon quantum dot layer arranged between the anode and the hole transport layer can effectively prevent the acidity of PEDOT and PSS from corroding the electrode, and can improve the charge transport capability between the electrode and the PEDOT and PSS hole transport layer by utilizing the excellent carrier transport performance of the carbon quantum dots. The first carbon quantum dot layer arranged between the hole transport layer and the quantum dot light emitting layer can effectively improve the conductivity of the PEDOT PSS hole transport layer, and light emitted by the quantum dot light emitting layer on one side of the PEDOT PSS hole transport layer can be effectively absorbed by the carbon quantum dots to perform photoelectric conversion, so that the light energy is further converted into energy required by carrier transmission, and the transmission capability of the PEDOT PSS hole transport layer can be effectively improved. In addition, carbon quantum dots in the first carbon quantum dot layer and the second carbon quantum dot layer can be well connected between PEDOT and PSS particles to form a three-dimensional interpenetrating conductive network structure, and direct charge transmission bridges are formed between isolated PEDOT and PSS to be connected and communicated to form an efficient conductive layer, so that the conductivity of the hole transmission layer is greatly improved. Meanwhile, the advantages of easy processability, flexibility and the like of PEDOT and PSS are retained, and the processability, flexibility, conductivity and the like of the hole transport material are improved.
In some embodiments, the quantum dot light emitting diode comprises a cathode and an anode which are oppositely arranged, a quantum dot light emitting layer arranged between the cathode and the anode, a PEDOT: PSS hole transport layer arranged between the anode and the quantum dot light emitting layer, a second carbon quantum dot layer with the thickness of 20-40 nanometers arranged between the anode and the PEDOT: PSS hole transport layer, and a first carbon quantum dot layer with the thickness of 20-40 nanometers arranged between the PEDOT: PSS hole transport layer and the quantum dot light emitting layer, wherein the first carbon quantum dot layer and the second carbon quantum dot layer contain carbon quantum dots with functionalized amino groups. In addition, the quantum dot light emitting diode may further include an electron functional layer such as an electron transport layer disposed on the surface of the quantum dot light emitting layer, and a cathode disposed on the surface of the electron transport layer, as shown in fig. 3.
In some embodiments, the hole transport layer may also be a small organic molecule or a high molecular conductive polymer, including: TFB, PVK, TCTA, TAPC, Poly-TBP, Poly-TPD, NPB, CBP, MoO3、WoO3、NiO、CuO、V2O5CuS, and the like.
In some embodiments, materials of the quantum dot light emitting layer include, but are not limited to: at least one semiconductor compound of II-IV group, II-VI group, II-V group, III-VI group, IV-VI group, I-III-VI group, II-IV-VI group and II-IV-V group of the periodic table of elements or a core-shell structure semiconductor compound composed of at least two of the above semiconductor compounds, wherein the surface of the semiconductor compound contains a group VI atom. In some embodiments, the quantum dot material is selected from: at least one semiconductor nanocrystal compound of CdSe, CdS, CdTe, ZnO, ZnSe, ZnS, ZnTe, HgS, HgSe, HgTe and CdZnSe, or at least two semiconductor nanocrystal compounds with mixed type, gradient mixed type, core-shell structure type or combined type structures. In other specific embodiments, the quantum dot material is selected from: at least one semiconductor nanocrystal compound of InAs, InP, InN, GaN, InSb, InAsP, InGaAs, GaAs, GaP, GaSb, AlP, AlN, AlAs, AlSb, CdSeTe and ZnCdSe, or a semiconductor nanocrystal compound with a mixed type, a gradient mixed type, a core-shell structure type or a combined type and other structures formed by at least two components, wherein the surface of the semiconductor nanocrystal compound contains VI-group atoms. The quantum dot materials have the characteristics of quantum dots and have good photoelectric properties.
In some further embodiments, the materials of the quantum dot light emitting layer include, but are not limited to: at least one of a perovskite nanoparticle material (in particular a luminescent perovskite nanoparticle material), a metal nanoparticle material, a metal oxide nanoparticle material. The quantum dot materials have the characteristics of quantum dots and have good photoelectric properties.
In some embodiments, the surface of the quantum dot has attached thereto: at least one ligand selected from acid ligand, thiol ligand, amine ligand, phosphine oxide ligand, phospholipid, lecithin and polyvinyl pyridine. The surface of the quantum dot in the embodiment of the invention is also connected with ligands such as acid ligand, thiol ligand, amine ligand, phosphine oxide ligand, phospholipid, lecithin, polyvinyl pyridine and the like, and the existence of the ligands can further passivate the surface defect state of the quantum dot to a certain extent, and better maintain the stability of the lattice structure and the interface on the surface of the quantum dot, thereby improving the stability of the quantum dot and improving the luminous efficiency of the quantum dot layer. In some embodiments, the acid ligand is selected from: at least one of deca acid, undecenoic acid, tetradecanoic acid, oleic acid, and stearic acid. In some embodiments, the thiol ligand is selected from: at least one of octaalkylmercaptan, dodecylmercaptan and octadecylmercaptan. In some embodiments, the amine ligand is selected from: at least one of oleylamine, octadecylamine and octamine. In some embodiments, the phosphine ligand comprises: trioctylphosphine. In some embodiments, the phosphine oxide ligand comprises: trioctylphosphine oxide.
In some embodiments, the anode comprises ITO, FTO or ZTO and has a thickness of 30-150 nm.
In some embodiments, the electron transport layer comprises one or more of ZnO, ZnMgO, ZnMgLiO, ZnInO, ZrO, TiO2, Alq3, TAZ, TPBI, PBD, BCP, Bphen, and has a thickness of 10-120 nm.
In some embodiments, the cathode comprises: al, Ag, Au, Cu, Mo or their alloy, the thickness is 80-120 nm.
The quantum dot light-emitting diode provided by the embodiment of the invention can be prepared by the following method.
As shown in fig. 1 and 2, an embodiment of the present invention further provides a method for manufacturing a quantum dot light emitting diode, including the following steps:
s10, providing a hole transport layer, and depositing first carbon quantum dots on the hole transport layer to form a first carbon quantum dot layer;
s20, depositing a quantum dot material on the surface of the other side, far away from the hole transport layer, of the first carbon quantum dot layer to form a quantum dot light emitting layer;
alternatively, the first and second electrodes may be,
s01, providing a quantum dot light-emitting layer, and depositing a first carbon quantum dot on the quantum dot light-emitting layer to form a first carbon quantum dot layer;
and S02, depositing a hole transport material on the surface of the other side, far away from the quantum dot light emitting layer, of the first carbon quantum dot layer to form a hole transport layer.
According to the preparation method of the quantum dot light-emitting diode provided by the embodiment of the invention, the functional layers can be prepared from one side containing the hole transport layer, and the functional layers such as the first carbon quantum dot layer, the quantum dot light-emitting layer and the like are sequentially deposited on the hole transport layer; the preparation method is simple, is suitable for preparing the positive type structure quantum dot light-emitting diode and the inverse type structure quantum dot light-emitting diode, is flexible to operate and wide in adaptability, and can meet different application requirements.
The step of providing a hole transport layer includes:
providing a substrate deposited with an anode, and depositing second carbon quantum dots on the anode to form a second carbon quantum dot layer;
and depositing a hole transport material on the other side surface of the second carbon quantum dot layer far away from the anode to form the hole transport layer.
In some embodiments, a method for manufacturing a quantum dot light emitting diode according to an embodiment of the present invention includes:
s11, providing a substrate containing an anode, and depositing second carbon quantum dots on the anode to form a second carbon quantum dot layer;
s21, depositing a hole transport material on the surface of the other side, far away from the anode, of the second carbon quantum dot layer to form a hole transport layer;
s31, depositing first carbon quantum dots on the surface of the other side, far away from the second carbon quantum dot layer, of the hole transport layer to form a second carbon quantum dot layer;
s41, depositing a quantum dot material on the surface of the other side, far away from the hole transport layer, of the first carbon quantum dot layer to form a quantum dot light emitting layer.
The preparation method of the quantum dot light-emitting diode of the embodiment of the invention starts from a substrate containing an anode, and sequentially deposits a second carbon quantum dot, a hole transport material, a first carbon quantum dot and a quantum dot light-emitting layer on the anode, and sequentially prepares a first carbon quantum dot layer, a hole transport layer, a second carbon quantum dot layer and a quantum dot light-emitting layer on the surface of the anode.
In some embodiments, providing a substrate comprising an anode on which the second carbon quantum dots are deposited, the step of forming the second carbon quantum dot layer may be: and preparing the second carbon quantum dots into a solution with the concentration of 15-30 mg/ml, spin-coating the anode at the rotating speed of 3000-5000rpm for 10-20s, and drying at 60-100 ℃ to form a second carbon quantum dot layer.
In some embodiments, depositing a hole transport material on the other side surface of the second carbon quantum dot layer away from the anode may be: and spin-coating a hole transport layer material such as PEDOT (sodium dodecyl benzene sulfonate) -PSS solution on the other side surface of the first carbon quantum dot layer away from the anode for 30-60s at the speed of 3000-5000rpm, and then placing the first carbon quantum dot layer on a heating table and heating at 60-100 ℃ for 20-60min to form the hole transport layer.
In some embodiments, after the first carbon quantum dots are prepared into a solution with a concentration of 15-30 mg/ml, the other side surface of the hole transport layer away from the first carbon quantum dot layer is spin-coated at 3000-5000rpm for 10-20s, and dried at 60-100 ℃ to form the first carbon quantum dot layer.
In some embodiments, a substrate is provided with a cathode deposited sequentially, and an electron transport layer is spin-coated on the surface of the cathode (according to the parameters of 2000-4000rpm spin-coating time of 30-60s, and then placed on a heating table and heated at 60-100 ℃ for 20-60min to obtain the electron transport layer.
In some embodiments, the required quantum dots (the quantum dots can be common binary or ternary quantum dots, and can also be perovskite quantum dots) are spin-coated on the surface of the electron transport layer far away from the cathode according to the parameters of 1500-.
In other embodiments, a method for manufacturing a quantum dot light emitting diode according to an embodiment of the present invention includes:
s12, providing a substrate on which a cathode and a quantum dot light-emitting layer are sequentially deposited, and depositing a first carbon quantum dot on the surface of the other side, far away from the cathode, of the quantum dot light-emitting layer to form a first carbon quantum dot layer;
s22, depositing a hole transport material on the surface of the other side, far away from the quantum dot light emitting layer, of the first carbon quantum dot layer to form a hole transport layer;
and S32, depositing a second carbon quantum dot on the surface of the other side, far away from the first carbon quantum dot layer, of the hole transport layer to form a second carbon quantum dot layer.
The preparation method of the quantum dot light-emitting diode provided by the embodiment of the invention starts from a substrate containing a cathode, a quantum dot light-emitting layer, a first carbon quantum dot layer, a hole transport layer and a second carbon quantum dot layer are sequentially deposited and formed on the cathode, an electron transport layer is deposited between the cathode and the quantum dot light-emitting layer, and an anode prepared on the surface of the second carbon quantum dot layer through evaporation is used for preparing the quantum dot light-emitting diode with an inverted structure.
In some embodiments, after the first carbon quantum dot is prepared into a solution with a concentration of 15-30 mg/ml, spin-coating the surface of the other side of the quantum dot light-emitting layer away from the electron transport layer at a rotating speed of 3000-5000rpm for 10-20s, and drying at 60-100 ℃ to form a first carbon quantum dot layer.
In some embodiments, a hole transport layer material such as PEDOT: PSS solution is spin-coated on the other side surface of the first carbon quantum dot layer away from the quantum dot light emitting layer for 30-60s at a speed of 3000-.
In some embodiments, after the second carbon quantum dots are prepared into a solution with a concentration of 15-30 mg/ml, the other side surface of the hole transport layer away from the first carbon quantum dot layer is spin-coated at 3000-5000rpm for 10-20s, and dried at 60-100 ℃ to form a second carbon quantum dot layer.
In some embodiments, the preparation of the first carbon quantum dot and/or the second carbon quantum dot comprises the steps of: dissolving a carbon source and a nitrogen source in water, reacting for 3-8 hours under the pressurization condition of the temperature of 150-200 ℃, and then separating to obtain the carbon quantum dots. According to the carbon quantum dot disclosed by the embodiment of the invention, the carbon source and the nitrogen source are used as raw materials, and are subjected to high-temperature high-pressure hydrothermal synthesis, the surface of the prepared carbon quantum dot is connected with the amino active group, the amino functionalized carbon quantum dot has higher fluorescence intensity and high fluorescence quantum yield, the absorbed light energy can be better converted into energy required by carrier transmission, and the amino active group in the carbon quantum dot has better bonding tightness with an electrode, a hole transport layer material and a quantum dot light emitting layer. If the reaction temperature is too low or the reaction time is too short, the amount of byproducts is too large or even the carbon quantum dot material cannot be prepared.
In some embodiments, the step of dissolving the carbon and nitrogen sources in water comprises: according to the mass ratio of the carbon source, the nitrogen source and the water being (0.5-3): (1-5): (20-40), the carbon source and the nitrogen source are dissolved in water, the raw material components in the preparation ratio enable all substances to be in full contact reaction to generate a carbon quantum dot material, meanwhile, the amino functionalization of the carbon quantum dot is effectively ensured, the surface of the prepared carbon quantum dot is connected with an amino active group, the fluorescence intensity of the carbon quantum dot is enhanced, the capacity of the carbon quantum dot for absorbing light energy and converting the light energy into a carrier is improved, and the bonding tightness between the carbon quantum dot and an adjacent functional layer is enhanced.
In some embodiments, the carbon source comprises: at least one of citric acid, glucose, vitamins, fructose, sucrose, and lactic acid. In some embodiments, the nitrogen source comprises: urea and/or amino acids. The carbon source and the nitrogen source adopted by the embodiment of the invention can generate the carbon quantum dot material under the conditions of high temperature, high pressure and high hydrothermal.
In some embodiments, the carbon source and the nitrogen source are dissolved in water, and react for 3-8 hours under the high-pressure condition that the temperature is 150-200 ℃ and the pressure is 10-100 MPa, so that the carbon source and the nitrogen source generate a carbon quantum dot material through a hydrothermal reaction, and the carbon quantum dot is obtained through separation and purification.
In some embodiments, the carbon source and the nitrogen source are dissolved in water, and after reaction for 3-8 hours under the high pressure condition of 150-200 ℃ and 10-100 MPa, a dialysis device (such as a dialysis bag) with a molecular weight cutoff of 3500 or more is used to separate the mixed solution after the pressure reaction, and then the carbon quantum dots are obtained after drying. After the dialysis bag with the molecular weight cutoff more than or equal to 3500 is adopted to separate the mixed solution after the pressure reaction, the carbon quantum dot product is not affected, and the separation and purification purity is high.
In some specific embodiments, 0.5-3g of citric acid and 1-5g of urea are weighed and dissolved in 20-40ml of deionized water, the mixture is stirred uniformly to be fully dissolved, then the solution is transferred to a high-pressure hydrothermal reaction kettle, the temperature is heated to 150 ℃ and 200 ℃, the solution is kept for 3-8 hours, then the solution is taken out to be naturally cooled, the cooled solution is filled into a dialysis bag with the specification of MWCO3500, dialysis is carried out at room temperature for 24-48 hours, and then the required carbon quantum dot solution can be obtained, and the carbon quantum dot is obtained after drying.
In some embodiments, the thickness of the second carbon quantum dot layer is 20-40 nm, and the second carbon quantum dot layer with the thickness can effectively prevent the corrosion of hole transport materials such as PEDOT, PSS and the like to the electrode, ensure that the electrode is not corroded, and ensure that the contact surface is relatively flat and does not form a large contact barrier to influence the transmission of carriers.
In some embodiments, the thickness of the first carbon quantum layer is 20-40 nm, the flatness of the first carbon quantum dot layer film layer with the thickness is good, a large contact barrier cannot be formed to influence the transmission of carriers, light emitted by the quantum dot light-emitting layer close to one side of the hole transmission layer can be absorbed and converted into energy required by the transmission of the carriers, and the transmission capability of the hole transmission layer is effectively improved.
In order to make the above implementation details and operations of the present invention clearly understood by those skilled in the art and obviously show the advanced performance of the quantum dot light emitting diode and the manufacturing method thereof according to the embodiment of the present invention, the above technical solution is illustrated by a plurality of embodiments.
Example 1
A quantum dot light emitting diode comprises the following preparation steps:
clearing the surface of the ITO electrode. The purchased ITO glass sheet was cut into 1.5cm by 1.5cm squares. Then cleaning, namely putting the ITO glass into a cleaning agent solution for ultrasonic treatment; then the ITO glass sheet is ultrasonically cleaned in acetone for 15 minutes; finally, carrying out ultrasonic treatment in isopropanol solution for 15 minutes; before use, the ITO glass sheet is blown dry by a nitrogen gun for standby.
Spin coating the first carbon quantum dot layer. The prepared quantum dots are prepared into 20mg/ml ethanol solution, then spin coating is carried out according to the parameters of 3000-5000rpm and 10-20s of spin coating time, and then the quantum dots are placed on a heating platform and heated at 60-100 ℃ for 20-60min, so as to remove the solvent in the quantum dots.
And thirdly, PEDOT is a PSS hole transport layer. PSS solution is spin-coated according to the parameters of 3000-5000rpm and 30-60s of spin-coating time, and then the solution is placed on a heating table and heated at 60-100 ℃ for 20-60min, so as to remove the solvent in the solution.
And spin coating the second carbon quantum dot layer. The prepared quantum dots are prepared into 20mg/ml ethanol solution, then spin coating is carried out according to the parameters of 3000-5000rpm and 10-20s of spin coating time, and then the quantum dots are placed on a heating platform and heated at 60-100 ℃ for 20-60min, so as to remove the solvent in the quantum dots.
And (6) spin coating the quantum dot light-emitting layer. The CdS/ZnS quantum dots are subjected to spin coating according to the parameters of 1500-.
Spin coating electron transport layer. The zinc oxide electron transport layer material is spin-coated according to the parameters of 2000-4000rpm and the spin-coating time of 30-60s, and then the zinc oxide electron transport layer material is placed on a heating table and heated at 60-100 ℃ for 20-60min, so that the solvent in the zinc oxide electron transport layer material is removed, and the crystallization performance of the zinc oxide electron transport layer material can be improved.
Vapor deposition of an aluminum electrode is carried out on the surface of the electron transport layer, and the quantum dot light-emitting diode is obtained.
Comparative example 1
A quantum dot light emitting diode comprises the following preparation steps:
clearing the surface of the ITO electrode. The purchased ITO glass sheet was cut into 1.5cm by 1.5cm squares. Then cleaning, namely putting the ITO glass into a cleaning agent solution for ultrasonic treatment; then the ITO glass sheet is ultrasonically cleaned in acetone for 15 minutes; finally, carrying out ultrasonic treatment in isopropanol solution for 15 minutes; before use, the ITO glass sheet is blown dry by a nitrogen gun for standby.
PEDOT: PSS hole transport layer. PSS solution is spin-coated according to the parameters of 3000-5000rpm and 30-60s of spin-coating time, and then the solution is placed on a heating table and heated at 60-100 ℃ for 20-60min, so as to remove the solvent in the solution.
And thirdly, spin coating of the quantum dot light emitting layer. The CdS/ZnS quantum dots are subjected to spin coating according to the parameters of 1500-.
And fourthly, spin coating the electron transport layer. The zinc oxide electron transport layer material is spin-coated according to the parameters of 2000-4000rpm and the spin-coating time of 30-60s, and then the zinc oxide electron transport layer material is placed on a heating table and heated at 60-100 ℃ for 20-60min, so that the solvent in the zinc oxide electron transport layer material is removed, and the crystallization performance of the zinc oxide electron transport layer material can be improved.
And (6) carrying out evaporation plating of an aluminum electrode on the surface of the electron transport layer to obtain the quantum dot light-emitting diode.
Furthermore, in order to verify the progress of the quantum dot light-emitting diode prepared by the embodiment of the invention, the embodiment of the invention is subjected to performance test.
Test example 1
The test example tests the sheet resistance of the first carbon quantum dot/PEDOT: PSS/second carbon quantum dot composite hole transport layer in the quantum dot light emitting diode prepared in example 1 and the sheet resistance of the PEDOT: PSS hole transport layer in the quantum dot light emitting diode prepared in comparative example 2, and the external quantum efficiency of the quantum dot light emitting diodes of example 1 and comparative example 1, and the test structures are shown in table 1 below:
Figure BDA0002347203970000151
from the above test results, it can be seen that the sheet resistance of the composite hole transport in the quantum dot light emitting diode prepared in example 1 of the present invention, in which the first carbon quantum dot layer and the second carbon quantum dot layer are respectively disposed on both sides of the hole transport layer, is 14 Ω/os, which is lower than the sheet resistance (16.5 Ω/os) of the hole transport layer in comparative example 1, in which no carbon quantum dot layer is disposed, and the quantum dot light emitting diode prepared in example 1 has higher external quantum efficiency, which indicates that the quantum dot light emitting diode prepared in example of the present invention has stronger charge transport capability.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.

Claims (11)

1. The quantum dot light-emitting diode is characterized by comprising a hole transport layer, a quantum dot light-emitting layer and a first carbon quantum dot layer, wherein the first carbon quantum dot layer is arranged between the hole transport layer and the quantum dot light-emitting layer, and the first carbon quantum dot layer comprises a plurality of first carbon quantum dots.
2. The quantum dot light emitting diode of claim 1, further comprising a second carbon quantum dot layer and an anode, the second carbon quantum dot layer disposed between the anode and the hole transport layer, the second carbon quantum dot layer comprising a number of second carbon quantum dots.
3. The qd-led of claim 2, wherein the thickness of the first carbon quantum dot layer is 20nm to 40 nm; and/or the presence of a gas in the gas,
the thickness of the second carbon quantum layer is 20-40 nanometers.
4. The QD LED of claim 2 or 3 wherein the first carbon quantum dot is an amino-functionalized carbon quantum dot, and/or,
the second carbon quantum dots are amino-functionalized carbon quantum dots.
5. A preparation method of a quantum dot light-emitting diode is characterized by comprising the following steps:
providing a hole transport layer, and depositing first carbon quantum dots on the hole transport layer to form a first carbon quantum dot layer;
depositing a quantum dot material on the surface of the other side, far away from the hole transport layer, of the first carbon quantum dot layer to form a quantum dot light-emitting layer;
alternatively, the first and second electrodes may be,
providing a quantum dot light-emitting layer, and depositing a first carbon quantum dot on the quantum dot light-emitting layer to form a first carbon quantum dot layer;
and depositing a hole transport material on the surface of the other side, far away from the quantum dot light emitting layer, of the first carbon quantum dot layer to form a hole transport layer.
6. The method of claim 5, wherein the step of providing a hole transport layer comprises:
providing a substrate deposited with an anode, and depositing second carbon quantum dots on the anode to form a second carbon quantum dot layer;
and depositing a hole transport material on the other side surface of the second carbon quantum dot layer far away from the anode to form the hole transport layer.
7. The method of claim 6, wherein the preparing of the first carbon quantum dot and/or the second carbon quantum dot comprises the steps of: dissolving a carbon source and a nitrogen source in water, reacting for 3-8 hours under the pressurization condition of the temperature of 150-200 ℃, and then separating to obtain the carbon quantum dots.
8. The method of claim 7, wherein the step of dissolving the carbon source and the nitrogen source in water comprises: according to the mass ratio of the carbon source, the nitrogen source and the water being (0.5-3): (1-5): (20-40) dissolving the carbon source and the nitrogen source in water; and/or the presence of a gas in the gas,
the step of the separation process comprises: separating the mixed solution after the pressure reaction by adopting a dialysis device with the molecular weight cutoff more than or equal to 3500 to obtain carbon quantum dots; and/or the presence of a gas in the gas,
the pressure under the pressurizing condition is 10-100 MPa.
9. The method for preparing a quantum dot light-emitting diode according to any one of claims 7 to 8, wherein the carbon source comprises: at least one of citric acid, glucose, vitamins, fructose, sucrose, and lactic acid; and/or the presence of a gas in the gas,
the nitrogen source comprises: urea and/or amino acids.
10. The method of claim 9, wherein the conditions for depositing the first carbon quantum dots comprise: preparing the first carbon quantum dots into a solution with the concentration of 15-30 mg/ml, spin-coating at the rotating speed of 3000-5000rpm for 10-20s, and drying to form a first carbon quantum dot layer; and/or the presence of a gas in the gas,
the conditions for depositing the second carbon quantum dots include: and preparing the second carbon quantum dots into a solution with the concentration of 15-30 mg/ml, spin-coating at the rotating speed of 3000-5000rpm for 10-20s, and drying to form a second carbon quantum dot layer.
11. The method of any one of claims 6 to 7, wherein the first carbon quantum dot layer has a thickness of 20 to 40 nm; and/or the presence of a gas in the gas,
the thickness of the second carbon quantum layer is 20-40 nanometers; and/or the presence of a gas in the gas,
PSS, wherein the hole transport layer material comprises PEDOT.
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Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102610725A (en) * 2012-03-29 2012-07-25 华北电力大学 Semiconductor quantum dot light-emitting diode and preparing method thereof
KR20180035278A (en) * 2016-09-28 2018-04-06 경북대학교 산학협력단 Quantum dots based light emitting device and method of manufacturing the same
CN108649144A (en) * 2018-05-08 2018-10-12 电子科技大学 A kind of perovskite light emitting diode and preparation method thereof based on composite hole transporting layer
WO2018188155A1 (en) * 2017-04-14 2018-10-18 深圳市华星光电半导体显示技术有限公司 Quantum dot display device and manufacturing method therefor
CN108767123A (en) * 2018-06-07 2018-11-06 吉林大学 A kind of perovskite solar cell and preparation method thereof based on water solubility and alcohol-soluble carbon quantum dot co-doped
CN109935706A (en) * 2017-12-15 2019-06-25 Tcl集团股份有限公司 A kind of QLED device and preparation method thereof
CN109980096A (en) * 2017-12-27 2019-07-05 Tcl集团股份有限公司 QLED device and preparation method thereof
CN110350098A (en) * 2019-07-16 2019-10-18 华北电力大学 A kind of hole transmission layer and a kind of light emitting diode and preparation method thereof

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102610725A (en) * 2012-03-29 2012-07-25 华北电力大学 Semiconductor quantum dot light-emitting diode and preparing method thereof
KR20180035278A (en) * 2016-09-28 2018-04-06 경북대학교 산학협력단 Quantum dots based light emitting device and method of manufacturing the same
WO2018188155A1 (en) * 2017-04-14 2018-10-18 深圳市华星光电半导体显示技术有限公司 Quantum dot display device and manufacturing method therefor
CN109935706A (en) * 2017-12-15 2019-06-25 Tcl集团股份有限公司 A kind of QLED device and preparation method thereof
CN109980096A (en) * 2017-12-27 2019-07-05 Tcl集团股份有限公司 QLED device and preparation method thereof
CN108649144A (en) * 2018-05-08 2018-10-12 电子科技大学 A kind of perovskite light emitting diode and preparation method thereof based on composite hole transporting layer
CN108767123A (en) * 2018-06-07 2018-11-06 吉林大学 A kind of perovskite solar cell and preparation method thereof based on water solubility and alcohol-soluble carbon quantum dot co-doped
CN110350098A (en) * 2019-07-16 2019-10-18 华北电力大学 A kind of hole transmission layer and a kind of light emitting diode and preparation method thereof

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
乔文远等: "基于WO_x/PEDOT:PSS复合空穴传输层的高效稳定平面异质结钙钛矿太阳电池", 《电化学》 *

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