Preparation method of quantum dot infrared detector and quantum dot infrared detector
By introducing quantum dot stabilizers into quantum dot infrared detectors, the oxidation and ionization of quantum dot ligands under high temperature and electric field are solved, and carrier mobility and device performance are improved, thereby achieving higher external quantum efficiency and lower dark currents.
Patent Information
- Application Number
- CN202411646783.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-18
- Publication Date
- 2025-02-25
AI Technical Summary
Under the action of high temperature and electric field, the ligands of quantum dots are easily oxidized, and the ligands of ligands are poor in ionization and low ion mobility, which limit the performance of the device.
The quantum dot stabilizer is introduced into the quantum dot dispersant system, and the quantum dot ionization and passivation of quantum dot ligands are promoted through the quantum dot stabilizer, thereby improving carrier mobility and device performance.
The external quantum efficiency (EQE) of the quantum dot infrared detector is improved and the dark current is reduced, which enhances the imaging effect and stability of the device.
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Figure CN119521997A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of infrared detection technology, and in particular to a method for preparing a quantum dot infrared detector and a quantum dot infrared detector. Background Art
[0002] Infrared light is a form of electromagnetic radiation that is ubiquitous in natural and artificial environments. Infrared imaging technology has greater application potential in emerging fields such as intelligent sensing, machine vision, and autonomous driving. However, infrared light cannot be directly perceived by the naked eye. Therefore, infrared photodetectors were invented to detect infrared light, and photoactive materials play a vital role in this process, among which semiconductor materials are usually used. Commercial infrared photodetectors are usually made of traditional narrow-bandgap bulk inorganic semiconductors (such as InSb, Ge, HgCdTe, InGaAs). However, bulk semiconductor materials are quite limited. First, they are usually grown under extreme temperature and vacuum conditions, which is very costly. Second, the epitaxial growth method commonly used is epitaxial growth on a lattice-matched crystal substrate, which makes this type of infrared photodetector expensive, inflexible, and limited. Therefore, there is an urgent need for alternative materials for infrared detectors with small size, low dark current, and low energy consumption.
[0003] Compared with traditional bulk semiconductors, infrared quantum dots have the advantages of easy processing, good flexibility and photostability, and high absorption coefficient. Colloidal quantum dot infrared detectors have the advantages of adjustable corresponding bands, excellent detection performance, low price, and process compatibility. They have shown great potential to replace silicon-based pixel arrays and achieve full coverage imaging in the short-wave infrared band.
[0004] In quantum dot infrared detectors, the quantum dot functional layer directly affects the performance of the device, and the quantum dot functional layer film is usually obtained by liquid-phase ligand exchange and re-dispersion spin coating of quantum dots; during the operation of the device, the quantum dot functional layer is easily affected by high temperature and electric field, which makes the quantum dot ligands easily oxidized, and the quantum dot ligands have poor ionization effect and low ion mobility, which limits the performance of the device.
[0005] Application Contents
[0006] In view of the above problems, the present application provides a method for preparing a quantum dot infrared detector and a quantum dot infrared detector.
[0007] In a first aspect, a method for preparing a quantum dot infrared detector is provided, comprising:
[0008] A method for preparing a quantum dot infrared detector, characterized by comprising:
[0009] preparing quantum dot stabilizers, and preparing quantum dots;
[0010] Based on the quantum dot stabilizer, the quantum dot dispersant is obtained, and the quantum dots are added into the quantum dot dispersant to obtain an active layer precursor, wherein the quantum dot stabilizer is used to passivate the quantum dots;
[0011] An active layer is prepared based on the active layer precursor, thereby preparing the quantum dot infrared detector.
[0012] The steps of preparing the quantum dot stabilizer include:
[0013] The dimethylamine solution and the ethanol solution are mixed and stirred to obtain a first mixed solution;
[0014] Formic acid is added dropwise to the first mixed solution, and the mixture is stirred and vacuum rotary evaporated to obtain the quantum dot stabilizer.
[0015] The steps of preparing quantum dots include:
[0016] adding PbS quantum dots into an n-octane solution to obtain a quantum dot solution;
[0017] Add PbI2 and PbBr2 into dimethylformamide solution to obtain ligand solution;
[0018] The quantum dot solution and the ligand solution are mixed and ligand exchange is performed to obtain the quantum dots.
[0019] The step of mixing the quantum dot solution and the ligand solution and performing ligand exchange to obtain the quantum dots comprises:
[0020] Mixing and shaking the quantum dot solution and the ligand solution, and removing the upper solution;
[0021] Add n-octane solution, shake and wash, and remove the upper solution;
[0022] The lower layer solution after removing the upper layer solution is centrifuged, the upper layer solution is removed, and the solution is drained to obtain the quantum dots.
[0023] Wherein, the step of obtaining the quantum dot dispersant based on the quantum dot stabilizer comprises:
[0024] The quantum dot stabilizer, dimethylformamide, dimethyl sulfoxide, and butylamine are mixed according to a first preset ratio to obtain the quantum dot dispersant;
[0025] The step of adding the quantum dots into the quantum dot dispersant to obtain an active layer precursor comprises:
[0026] The quantum dots and the quantum dot dispersant are mixed, stirred or shaken, and centrifuged according to a second preset ratio to obtain an active layer precursor.
[0027] Wherein, the volume ratio of the quantum dot stabilizer to the dimethylformamide is in the range of 1:50 to 1:20.
[0028] The steps of preparing the active layer based on the active layer precursor to prepare the quantum dot infrared detector include:
[0029] preparing a bottom electrode layer;
[0030] preparing an electron blocking layer on the bottom electrode layer;
[0031] Prepare a P-type layer on a surface of the electron blocking layer away from the bottom electrode layer;
[0032] Using the active layer precursor to prepare the active layer on a surface of the P-type layer away from the bottom electrode layer;
[0033] Preparing an electron transport layer on a surface of the active layer away from the bottom electrode layer;
[0034] Prepare a strong n-type layer on a surface of the electron transport layer away from the bottom electrode layer;
[0035] A top electrode layer is prepared on a surface of the strong n-type layer away from the bottom electrode layer.
[0036] Wherein, the materials of the top electrode layer and the bottom electrode layer are indium tin oxide;
[0037] The material of the electron blocking layer is NiOX;
[0038] The material of the p-type layer is PbS;
[0039] The material of the electron transport layer is C60;
[0040] The material of the strong n-type layer is SnO2.
[0041] The step of preparing the bottom electrode layer includes:
[0042] Sputtering an indium tin oxide film by magnetron sputtering, and patterning the indium tin oxide film by laser etching / photolithography / nanoimprinting process to form a bottom electrode layer;
[0043] The step of preparing an electron blocking layer on the bottom electrode layer comprises:
[0044] The electron blocking layer is prepared by vacuum magnetron sputtering a NiO-Li target on the bottom electrode layer;
[0045] The step of preparing a P-type layer on a surface of the electron blocking layer away from the bottom electrode layer comprises:
[0046] PbS quantum dots with tetramethylsilane as ligand were dissolved in octane, the p-type layer precursor solution;
[0047] Spin coating a p-type layer precursor solution on a surface of the electron blocking layer away from the bottom electrode layer;
[0048] A mixed solution of 1,2-ethanedithiol and acetonitrile is spin-coated on the p-type layer precursor solution to perform ligand exchange, thereby preparing the p-type layer.
[0049] In a second aspect, the present application provides a quantum dot infrared detector, which is prepared by any of the above-mentioned methods for preparing a quantum dot infrared detector.
[0050] The technical solution provided in the embodiments of the present application introduces a quantum dot stabilizer into the active layer. Since the quantum dot stabilizer itself is ionic, it can improve the carrier mobility of the quantum dots and improve the performance of the device, such as improving the external quantum efficiency (EQE) and reducing the dark current. At the same time, the quantum dot stabilizer itself has an amino functional group, so it can passivate the surface of the quantum dots. The quantum dot stabilizer itself is in ionic form, so it has a certain stability, and its system will not be affected by either photothermal aging or water-oxygen aging.
[0051] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS
[0052] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Also, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:
[0053] Figure 1 It is a schematic flow chart of the first embodiment of the method for preparing a quantum dot infrared detector of the present application;
[0054] Figure 2 yes Figure 1 A schematic flow chart of an embodiment of step S13;
[0055] Figure 3 It is a schematic structural diagram of an embodiment of a quantum dot infrared detector of the present application. DETAILED DESCRIPTION
[0056] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present disclosure and to be able to fully convey the scope of the present disclosure to those skilled in the art. In addition, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessary confusion of the concepts of the present disclosure.
[0057] Various structural schematic diagrams according to embodiments of the present disclosure are shown in the accompanying drawings. These figures are not drawn to scale, and some details are magnified and some details may be omitted for the purpose of clear expression. The shapes of various regions and layers shown in the figures and the relative sizes and positional relationships therebetween are only exemplary, and may deviate in practice due to manufacturing tolerances or technical limitations, and those skilled in the art may further design regions / layers with different shapes, sizes, and relative positions according to actual needs.
[0058] In quantum dot infrared detectors, the quantum dot functional layer directly affects the performance of the device, and the quantum dot functional layer film is usually obtained by liquid-phase ligand exchange and re-dispersion spin coating of quantum dots; during the operation of the device, the quantum dot functional layer is easily affected by high temperature and electric field, which makes the quantum dot ligands easily oxidized, and the quantum dot ligand ionization effect is poor, and the ion mobility is low, which limits the performance of the device. The present application introduces a quantum dot stabilizer into the quantum dot dispersant system, promotes the ion mobility of the quantum dot ligands through the quantum dot stabilizer, and passivates the quantum dots, thereby improving the imaging effect and stability of the quantum dot infrared detector.
[0059] The ultrasonic imaging device of the present application is described in detail below with reference to the accompanying drawings.
[0060] See first Figure 1 , Figure 1 This is a schematic flow chart of the first embodiment of the method for preparing a quantum dot infrared detector of the present application, which specifically includes:
[0061] Step S11: preparing a quantum dot stabilizer and preparing quantum dots.
[0062] In the present application, it is first necessary to prepare a quantum dot stabilizer. In one embodiment, the quantum dot stabilizer is prepared by stirring dimethylamine and formic acid. Specifically, the dimethylamine solution and the ethanol solution are mixed and stirred to obtain a first mixed solution; formic acid is added dropwise to the first mixed solution, stirred, and vacuum rotary evaporated to obtain the quantum dot stabilizer. Specifically, 20 ml of dimethylamine solution and 100 ml of ethanol are added to a beaker and stirred in an ice water bath for 30 minutes. Then an equal amount of 20 ml of formic acid is dropped into the diluted amine solution (ie, the first mixed solution), and finally, after continuous stirring for 4 hours, the obtained solution is vacuum rotary evaporated at 45°C for 2 hours to finally obtain a quantum dot stabilizer.
[0063] Specifically, the process of preparing quantum dots includes preparing a quantum dot solution and a ligand solution, mixing the quantum dot solution and the ligand solution, and performing ligand exchange to obtain quantum dots.
[0064] The preparation of the quantum dot solution includes: adding PbS quantum dots to an n-octane solution to obtain a quantum dot solution. Specifically, 2 to 20 ml (e.g., 10 ml) of PbS quantum dots with an n-octane solution as a solvent are prepared in a glove box at a concentration of 5 to 20 mg / mL (e.g., 10 mg / mL), and then stirred and shaken and filtered through a 0.22 um organic filter head to obtain a quantum dot solution, and the quantum dot solution is filtered in a glass bottle for later use.
[0065] The preparation of the ligand solution includes: adding PbI2 and PbBr2 to a dimethylformamide solution to obtain a ligand solution. Specifically, 2 to 3 mmol of PbI2 (in the experiment, 2.6 mmol of PbI2 can be weighed) and 0.2 to 0.3 mmol of PbBr2 (in the experiment, 0.26 mmol of PbBr2 can be weighed) are weighed and added to a centrifuge tube, and then 5 to 20 mL (for example, 10 mL) of dimethylformamide is added to prepare a ligand solution, and the ligand solution is obtained by filtering with a 0.22 um organic filter head after ultrasonic vibration, and the ligand solution is filtered in a glass bottle for later use.
[0066] The quantum dot solution and the ligand solution are mixed, and the ligand exchange is performed to obtain the quantum dots. Specifically, the quantum dot solution and the ligand solution are mixed and shaken, and the upper solution is removed. Specifically, 10ml of PbS quantum dot solution and 10ml of ligand solution are mixed in a 50ml glass bottle, and the lid is covered and shaken vigorously for 1min. The upper octane phase changes to clear, and the lower dimethylformamide phase changes to black. The upper solution is taken out and discarded. Add n-octane solution, shake and wash, and remove the upper solution. Specifically, add 10ml of n-octane to the glass bottle, shake for 2min, take out and discard the upper solution, and repeat three times. The lower solution after removing the upper solution is centrifuged, the upper solution is removed, and the quantum dots are obtained. Specifically, the lower solution is evenly divided into two 10mL centrifuge tubes and centrifuged at a speed of 9000r / min for 5min. After centrifugation, the upper clear liquid is discarded, and the centrifuge tube is placed in a vacuum chamber to drain the solvent to obtain quantum dot powder.
[0067] Step S12: obtaining the quantum dot dispersant based on the quantum dot stabilizer, and adding the quantum dots into the quantum dot dispersant to obtain an active layer precursor, wherein the quantum dot stabilizer is used to passivate the quantum dots.
[0068] In one embodiment, the quantum dot stabilizer, dimethylformamide, dimethyl sulfoxide, and butylamine are mixed according to a first preset ratio to obtain the quantum dot dispersant. Specifically, the ratio of dimethylformamide: quantum dot stabilizer: dimethyl sulfoxide: butylamine is 338:12:250:400 to obtain a mixed solvent, which is a quantum dot dispersant. It should be noted that when configuring the quantum dot dispersant, the volume ratio of the quantum dot stabilizer and the dimethylformamide ranges from 1:50 to 1:20.
[0069] The quantum dots and the quantum dot dispersant are mixed, stirred or shaken, and centrifuged according to a second preset ratio to obtain an active layer precursor. Take m quantum dots, take an appropriate amount of quantum dot dispersant in a small centrifuge tube according to the weight of the quantum dots m to prepare a 300mg / ml quantum dot solution, stir slightly or shake to accelerate dissolution, and obtain a PbS solution. Centrifuge the centrifuge tube in a centrifuge at a speed of 5000r / min for 1min to obtain an active layer precursor for standby use. Among them, the weight m of the quantum dots and the ratio of dimethylformamide, quantum dot stabilizer, dimethyl sulfoxide, and butylamine in the quantum dot dispersant can be adjusted according to actual conditions. These parameters affect the performance of the quantum dot infrared detector. In another embodiment, the ratio of dimethylformamide: quantum dot stabilizer: dimethyl sulfoxide: butylamine can also be prepared to be 344:6:250:400, and the amount of quantum dots is also adjusted based on this ratio. The amount of quantum dots is mainly based on the optimal performance of the device, and is not specifically limited.
[0070] Step S13: preparing an active layer based on the active layer precursor, thereby preparing the quantum dot infrared detector.
[0071] For details, please combine Figure 2 , step S13 specifically includes:
[0072] Step S131: preparing a bottom electrode layer.
[0073] In one embodiment, the material of the bottom electrode layer is indium tin oxide. Specifically, the indium tin oxide film is sputtered by magnetron sputtering, and the indium tin oxide film is patterned by laser etching / photolithography / nanoimprinting process to form the bottom electrode layer.
[0074] Step S132: preparing an electron blocking layer on the bottom electrode layer.
[0075] The material of the electron blocking layer is NiOX. The electron blocking layer is prepared by vacuum magnetron sputtering of a NiO-Li target on the bottom electrode layer. Specifically, vacuum magnetron sputtering of a NiO-Li target is performed on the bottom electrode layer. During the sputtering process, the amount of argon is 92, the sputtering power is 80 to 150 W, specifically 100 W, the sputtering time is 15 minutes, and during sputtering, the thickness is in the range of 40 to 80 nm, specifically 60 nm, to form an electron blocking layer.
[0076] Step S133: preparing a P-type layer on a surface of the electron blocking layer away from the bottom electrode layer.
[0077] The P-type layer material is PbS, specifically 1,2-ethanedithiol-modified PbS. In one embodiment,
[0078] PbS quantum dots with tetramethylsilane as ligands are dissolved in octane to prepare a p-type layer precursor solution; at this time, the PbS quantum dots are 880nm PbS quantum dots, which are different in size from the PbS quantum dots in the active layer. The p-type layer precursor solution is spin-coated on a surface of the electron blocking layer away from the bottom electrode layer; a mixed solution of 1,2-ethanedithiol and acetonitrile is spin-coated on the p-type layer precursor solution to perform ligand exchange, thereby preparing the p-type layer.
[0079] Specifically, on a surface of the electron blocking layer away from the bottom electrode layer, 10 to 40 mg / mL (e.g., 30 mg / mL) of a quantum dot solution with tetramethylsilane as a solvent and PbS as a solute is mixed evenly with an acetonitrile solution with a 1,2-ethanedithiol content of 0.01% to 1% (e.g., a 1,2-ethanedithiol content of 0.01%), and ligand exchange is performed to prepare a p-type layer. Specifically, a spin coating process is used, the spin coating thickness is 10 to 30 nm, for example, it can be 20 nm, and oxidation is performed in a high oxygen environment such as a drying tower, and the oxidation time is 12 to 24 hours, for example, the oxidation time can be 23 hours.
[0080] Step S134: using the active layer precursor to prepare the active layer on a surface of the P-type layer away from the bottom electrode layer.
[0081] In one embodiment, an active layer precursor can be spin-coated on a surface of the P-type layer away from the bottom electrode layer by spin coating, thereby forming an active layer. Specifically, turn on the spin coating system, set the rotation speed to 1500-2500r / min. In one embodiment, the rotation speed is set to 2500r / min, the time is set to 40s, and the acceleration is set to 500r / min. Spin coat the active layer precursor on the p-type layer, and place the wafer after spin coating on a hot plate at 50-100°C, such as 80°C, for annealing for 5-15 minutes. In one embodiment, the annealing time is 10 minutes to remove the amine organic solvent, thereby completing the preparation of the active layer.
[0082] Step S135: preparing an electron transport layer on a surface of the active layer away from the bottom electrode layer.
[0083] The material of the electron transport layer is C60. The device with the active layer prepared is placed on a thermal evaporation instrument, and the thermal evaporation C60 source is regulated by a film thickness meter, the evaporation rate is 0.08A / S, the thermal evaporation C60 thickness is 15nm to 30nm, preferably 15nm, and the thermal evaporation is terminated to form an electron transport layer.
[0084] Step S136: preparing a strong n-type layer on a surface of the electron transport layer away from the bottom electrode layer.
[0085] The device made of the electron transport layer is placed on an atomic layer deposition platform and evacuated; the device substrate platform and the tin source are heated to a preset temperature and then atomic layer deposition is performed. After the cycle number reaches 200, a SnO2 layer with a thickness of 30 to 50 nm is obtained, preferably with a thickness of 35 nm, to form a strong n-type layer.
[0086] Step S137: preparing a top electrode layer on a surface of the strong n-type layer away from the bottom electrode layer.
[0087] The magnetron sputtering method is used on a surface of the strong n-type layer away from the bottom electrode layer. During the sputtering process, the pressure is 1*10 -3 ~1*10 -2 pa, preferably at a pressure of 1*10 -3 Sputtering is carried out under pa, when indium tin oxide is sputtered, the oxygen-argon ratio is 0.1:28, the sputtering power is 100-200W, preferably 100W, the sputtering time is 20min, the top electrode layer is prepared, and finally a quantum dot infrared detector is prepared.
[0088] Because the quantum dot stabilizer itself is ionic, it can improve the carrier mobility of quantum dots and improve the performance of the device, such as improving the external quantum efficiency (EQE) and reducing the dark current; at the same time, the quantum dot stabilizer itself has an amino functional group, so it can passivate the surface of the quantum dots, and the quantum dot stabilizer itself is in ionic form, so it has a certain stability, and neither photothermal aging nor water and oxygen aging will affect its system.
[0089] See also Figure 3 , Figure 3 This is a structural schematic diagram of an embodiment of a quantum dot infrared detector of the present application. The quantum dot infrared detector of the present application is prepared by the method described above, and the quantum dot infrared detector specifically includes: a bottom electrode layer 111, an electron blocking layer 112, a p-type layer 113, an active layer 114, an electron transport layer 115, a strong n-type layer 116, and a top electrode layer 117.
[0090] The active layer 114 is a PbS / PbX2 layer, which can absorb the energy of photons under the irradiation of 1550nm light and generate optical signals. The electron blocking layer 112, the p-type layer 113, the active layer 114, the electron transport layer 115, and the strong n-type layer 116 form an ohmic contact between the bottom electrode layer 111 and the top electrode layer 117. The electron blocking layer 112, the p-type layer 113, the active layer 114, the electron transport layer 115, and the strong n-type layer 116 form a pin structure as a whole. Under the irradiation of 1550nm light, the active layer 114 will generate electrons and vacancies, and the electrons will go along the electron transport layer 115 to the strong n-type layer 116; the vacancies will reach the p-type layer 113. The electron blocking layer 112 prevents electrons from traveling back from the active layer 114 to the p-type layer 113. The p-type layer 113 forms a pn junction (light-emitting diode structure) with the strong n-type layer 116. The p-type layer 113 generates carriers. As the bias voltage increases, the built-in potential of the initial built-in electric field begins to change. When the p-type layer 113 is completely depleted, the photocurrent is maximum. The net photocurrent is obtained by subtracting the initial dark current from the photocurrent. The optical signal per unit area is the responsivity of 1550nm light.
[0091] The material of the bottom electrode layer 111 is the same as that of the top electrode layer 117 , both of which are indium tin oxide thin films.
[0092] The material of the strong n-type layer 116 is SnO 2 .
[0093] The material of the electron transport layer 115 is C 60 .
[0094] The material of the p-type layer 113 includes one or a mixture of PbS, 1,2-ethanedithiol, tetramethylsilane, and acetonitrile.
[0095] The material of the electron blocking layer 112 is NiOX.
[0096] The electron blocking layer 112 is of p-type, the active layer 114 is of i-type, and the electron transport layer 115 is of n-type.
[0097] A quantum dot stabilizer is introduced into the active layer 114. Since the quantum dot stabilizer itself is ionic, it can improve the carrier mobility of the quantum dots and improve the performance of the device, such as improving the external quantum efficiency (EQE) and reducing the dark current. At the same time, the quantum dot stabilizer itself has an amino functional group, so it can passivate the surface of the quantum dots. The quantum dot stabilizer itself is in ionic form, so it has a certain stability, and its system will not be affected by either photothermal aging or water-oxygen aging.
[0098] The algorithm and display provided herein are not inherently related to any particular computer, virtual system or other device. Various general purpose systems can also be used together with the teachings based on this. According to the above description, it is obvious that the structure required for constructing such systems. In addition, the application is not directed to any specific programming language either. It should be understood that various programming languages can be utilized to realize the content of the application described herein, and the description of the specific language above is for the purpose of disclosing the best mode of implementation of the application.
[0099] In the description provided herein, a large number of specific details are described. However, it is understood that the embodiments of the present application can be practiced without these specific details. In some instances, well-known methods, structures and techniques are not shown in detail so as not to obscure the understanding of this description.
[0100] Similarly, it should be understood that in order to streamline the present disclosure and assist in understanding one or more of the various aspects of the application, in the above description of exemplary embodiments of the present application, the various features of the present application are sometimes grouped together into a single embodiment, figure, or description thereof.
[0101] Those skilled in the art will appreciate that the modules in the device in the embodiment can be adaptively changed and arranged in one or more devices different from the embodiment. The modules or units or components in the embodiment can be combined into one module or unit or component, and in addition they can be divided into multiple submodules or subunits or subcomponents. Except that at least some of such features and / or processes or units are mutually exclusive, all features disclosed in this specification (including abstracts and drawings) and all processes or units of any method or device disclosed in this manner can be combined in any combination. Unless otherwise explicitly stated, each feature disclosed in this specification (including accompanying abstracts and drawings) can be replaced by alternative features that provide the same, equivalent or similar purposes.
[0102] Furthermore, those skilled in the art will appreciate that although some embodiments herein include certain features included in other embodiments but not other features, the combination of features from different embodiments is meant to be within the scope of the present application and to form different embodiments.
[0103] It should be noted that the above embodiments illustrate the present application rather than limit the present application. Any reference symbol between brackets should not be constructed as a limitation to the present application. The word "comprising" does not exclude the existence of components or steps not listed in the present application. The word "one" or "an" before a component does not exclude the existence of multiple such components. The present application can be implemented by means of hardware including several different components and by means of a suitably programmed computer. In the embodiments in which several devices are listed, several of these devices can be embodied by the same hardware item. The use of the words first, second, and third, etc. does not indicate any order. These words can be interpreted as names.
Claims
1. A method for preparing a quantum dot infrared detector, characterized in that: include: preparing quantum dot stabilizers, and preparing quantum dots; Based on the quantum dot stabilizer, the quantum dot dispersant is obtained, and the quantum dots are added into the quantum dot dispersant to obtain an active layer precursor, wherein the quantum dot stabilizer is used to passivate the quantum dots; An active layer is prepared based on the active layer precursor, thereby preparing the quantum dot infrared detector.
2. The preparation method according to claim 1, characterized in that: The steps of preparing the quantum dot stabilizer include: The dimethylamine solution and the ethanol solution are mixed and stirred to obtain a first mixed solution; Formic acid is added dropwise to the first mixed solution, and the mixture is stirred and vacuum rotary evaporated to obtain the quantum dot stabilizer.
3. The preparation method according to claim 1, characterized in that: The steps of preparing quantum dots include: adding PbS quantum dots into an n-octane solution to obtain a quantum dot solution; Add PbI2 and PbBr2 into dimethylformamide solution to obtain ligand solution; The quantum dot solution and the ligand solution are mixed and ligand exchange is performed to obtain the quantum dots.
4. The preparation method according to claim 3, characterized in that: The step of mixing the quantum dot solution and the ligand solution and performing ligand exchange to obtain the quantum dots comprises: Mixing and shaking the quantum dot solution and the ligand solution, and removing the upper solution; Add n-octane solution, shake and wash, and remove the upper solution; The lower layer solution after removing the upper layer solution is centrifuged, the upper layer solution is removed, and the solution is drained to obtain the quantum dots.
5. The preparation method according to claim 1, characterized in that: The step of obtaining the quantum dot dispersant based on the quantum dot stabilizer comprises: The quantum dot stabilizer, dimethylformamide, dimethyl sulfoxide, and butylamine are mixed according to a first preset ratio to obtain the quantum dot dispersant; The step of adding the quantum dots into the quantum dot dispersant to obtain an active layer precursor comprises: The quantum dots and the quantum dot dispersant are mixed, stirred or shaken, and centrifuged according to a second preset ratio to obtain an active layer precursor.
6. The preparation method according to claim 5, characterized in that: The volume ratio of the quantum dot stabilizer to the dimethylformamide is in the range of 1:50 to 1:
20.
7. The preparation method according to any one of claims 1 to 6, characterized in that: The steps of preparing an active layer based on the active layer precursor, thereby preparing the quantum dot infrared detector, include: preparing a bottom electrode layer; preparing an electron blocking layer on the bottom electrode layer; Prepare a P-type layer on a surface of the electron blocking layer away from the bottom electrode layer; Using the active layer precursor to prepare the active layer on a surface of the P-type layer away from the bottom electrode layer; Preparing an electron transport layer on a surface of the active layer away from the bottom electrode layer; Prepare a strong n-type layer on a surface of the electron transport layer away from the bottom electrode layer; A top electrode layer is prepared on a surface of the strong n-type layer away from the bottom electrode layer.
8. The preparation method according to claim 7, characterized in that: The top electrode layer and the bottom electrode layer are made of indium tin oxide; The material of the electron blocking layer is NiOX; The material of the p-type layer is PbS; The material of the electron transport layer is C60; The material of the strong n-type layer is SnO2.
9. The preparation method according to claim 7, characterized in that: The steps of preparing the bottom electrode layer include: Sputtering an indium tin oxide film by magnetron sputtering, and patterning the indium tin oxide film by laser etching / photolithography / nanoimprinting process to form a bottom electrode layer; The step of preparing an electron blocking layer on the bottom electrode layer comprises: The electron blocking layer is prepared by vacuum magnetron sputtering a NiO-Li target on the bottom electrode layer; The step of preparing a P-type layer on a surface of the electron blocking layer away from the bottom electrode layer comprises: PbS quantum dots with tetramethylsilane as ligand were dissolved in octane, the p-type layer precursor solution; Spin coating a p-type layer precursor solution on a surface of the electron blocking layer away from the bottom electrode layer; A mixed solution of 1,2-ethanedithiol and acetonitrile is spin-coated on the p-type layer precursor solution to perform ligand exchange, thereby preparing the p-type layer.
10. A quantum dot infrared detector, characterized in that: The quantum dot infrared detector is prepared by the method for preparing a quantum dot infrared detector according to any one of claims 1 to 9.