Photoelectric detector preparation method and photoelectric detector

Abstract

The invention provides a preparation method of a photoelectric detector and the photoelectric detector, and the method comprises the steps: preparing a quantum dot solution, and enabling quantum dots in the quantum dot solution to be wrapped by halogen; preparing a quantum dot dispersing agent by using a 2, 6-bis (aminomethyl) pyridine ligand; adding the quantum dot solution into the quantum dot dispersing agent to obtain an active layer precursor; and preparing an active layer based on the active layer precursor so as to prepare the photoelectric detector. The quantum dot dispersing agent prepared by introducing the 2, 6-bis (aminomethyl) pyridine ligand into the active layer can effectively passivate quantum dot surface defects which are not fully passivated by halogen ligands in a quantum dot solution, so that crystal face defects exposed by PbS CQDs are better passivated, and the photoelectric property of the photoelectric detector is effectively improved.

Description

Technical Field

[0001] The present application relates to the field of infrared detection technology, and in particular to a method for preparing a photoelectric detector and a photoelectric 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 photodetectors 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] At present, the PbS CQD image sensors reported in China have a photosensitive band below 1.3μm, and the functionality and advantages of infrared imaging are limited. It is urgent to develop PbS CQD materials with a detection wavelength that can reach the near-infrared II region (1.3-1.7μm). Due to the quantum confinement effect, the red shift of the detection wavelength corresponds to a larger CQD. As the size of quantum dots increases, the proportion of crystal faces increases, and the existing ligands in the system are difficult to effectively passivate the crystal faces, resulting in an increase in the sources of CQD defects, including an increase in dangling bonds, water and oxygen adsorption, particle agglomeration, and so on.

[0005] Application Contents

[0006] In view of the above problems, the present application provides a method for preparing a photoelectric detector and a photoelectric detector.

[0007] In a first aspect, a method for preparing a photodetector is provided, comprising:

[0008] preparing a quantum dot solution, wherein the quantum dots in the quantum dot solution are coated with halogen;

[0009] The quantum dot dispersant was prepared using 2,6-bis(aminomethyl)pyridine ligand;

[0010] adding the quantum dot solution into the quantum dot dispersant to obtain an active layer precursor;

[0011] An active layer is prepared based on the active layer precursor, thereby preparing the photodetector.

[0012] The step of preparing the quantum dot solution comprises:

[0013] preparing an initial quantum dot solution, in which quantum dots are encapsulated by oleic acid ligands;

[0014] Prepare ligand solution;

[0015] The initial quantum dot solution is mixed with the ligand solution to perform ligand exchange to obtain the quantum dot solution, wherein the quantum dots in the quantum dot solution are wrapped by halogen.

[0016] The step of preparing the initial quantum dot solution comprises:

[0017] Synthesis of zinc sulfide quantum dots using thioacetamide and zinc stearate;

[0018] Lead chloride and the zinc sulfide quantum dots are used to carry out cation exchange, the reaction time of the lead chloride and the zinc sulfide quantum dots is controlled, and the zinc sulfide quantum dots are added into n-octane, so as to obtain the initial quantum dot solution.

[0019] Wherein, the step of preparing the ligand solution comprises:

[0020] PbI2 and PbBr2 are mixed with N,N-dimethylformamide solution to obtain the ligand solution.

[0021] Wherein, the step of mixing the initial quantum dot solution with the ligand solution and performing ligand exchange to obtain the quantum dot solution comprises:

[0022] Filtering and mixing the initial quantum dot solution and the ligand solution according to a preset ratio, and shaking them sufficiently to perform ligand exchange;

[0023] Remove the upper solution, add n-octane, mix and shake, and remove the upper liquid;

[0024] The lower layer solution is centrifuged to remove the solvent to obtain the quantum dot solution.

[0025] The step of preparing a quantum dot dispersant using 2,6-bis(aminomethyl)pyridine ligand comprises:

[0026] preparing a quaternary dispersion system, wherein the quaternary dispersion system comprises N,N-dimethylformamide, dimethyl sulfoxide, n-butylamine, and 3-pyridinemethylamine;

[0027] The quantum dot dispersant is obtained by dissolving 2,6-bis(aminomethyl)pyridine ligand in N,N-dimethylformamide and adding a quaternary dispersion system.

[0028] The steps of preparing the active layer based on the active layer precursor to prepare the photodetector 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 a sacrificial layer on a surface of the active layer away from the bottom electrode layer;

[0034] Preparing an electron transport layer on a surface of the sacrificial layer away from the bottom electrode layer;

[0035] A top electrode layer is prepared on a surface of the electron transport 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 C 60 ;

[0040] The material of the electron transport 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 sacrificial layer on a surface of the active layer away from the bottom electrode layer comprises:

[0046] The film is deposited by thermal evaporation, and the C 60 , preparing a sacrificial layer on a surface of the active layer away from the bottom electrode layer;

[0047] The step of preparing an electron transport layer on a surface of the sacrificial layer away from the bottom electrode layer comprises:

[0048] The electron transport layer is prepared by coating a surface of the sacrificial layer away from the bottom electrode layer in an atomic layer deposition manner.

[0049] In a second aspect, the present application provides a photoelectric detector, which is prepared by any of the photoelectric detector preparation methods described above.

[0050] The technical solution provided in the embodiment of the present application introduces a quantum dot dispersant prepared by introducing 2,6-bis(aminomethyl)pyridine ligands into the active layer, which can effectively passivate the surface defects of quantum dots in the quantum dot solution that have not been fully passivated by the halogen ligands, so that the crystal plane defects exposed by PbS CQDs are better passivated, effectively improving the photoelectric performance of the photodetector.

[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 a first embodiment of a method for preparing a photoelectric detector of the present application;

[0054] Figure 2 yes Figure 1 A schematic flow chart of an embodiment of step S14;

[0055] Figure 3 It is a structural schematic diagram of an embodiment of the photoelectric 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] This application studies the passivation of CQD surface defects in the depletion region of the PbS CQD photodiode of the photodetector, analyzes the main defect types of large-sized PbS CQD, and proposes a new type of three-terminal ligand, 2,6-bis(aminomethyl)pyridine ligand, for auxiliary passivation in view of the problem that the crystal surface is difficult to effectively passivate. By adding 2,6-bis(aminomethyl)pyridine ligand to the dispersant, dissolving an appropriate amount of 2,6-bis(aminomethyl)pyridine ligand in N, N-dimethylformamide (DMF) dispersant, adding it to the existing quaternary dispersion system, and coating after sufficient oscillation and dispersion, the iodine-bromine-coated PbS CQD layer film defect suppression is achieved. The inhibitory effect of 2,6-bis(aminomethyl)pyridine ligand on CQD defects is verified by various means such as material characterization and device characterization, and finally a photodiode with low dark current is achieved.

[0059] The preparation method of the photoelectric detector 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 flow chart of a first embodiment of a method for preparing a photoelectric detector of the present application, which specifically includes:

[0061] Step S11: preparing a quantum dot solution, in which the quantum dots are wrapped by halogen.

[0062] The process of preparing the quantum dot solution in step S11 specifically includes:

[0063] 1) Preparing an initial quantum dot solution, in which quantum dots are encapsulated by oleic acid ligands.

[0064] Specifically, zinc sulfide quantum dots are synthesized using thioacetamide and zinc stearate; lead chloride and the zinc sulfide quantum dots are used for cation exchange, and the reaction time of the lead chloride and the zinc sulfide quantum dots is controlled, and the zinc sulfide quantum dots are added into n-octane to obtain the initial quantum dot solution.

[0065] In a specific embodiment, the PbS CQD used in the preparation of the photodetector light-absorbing layer is synthesized according to the cation exchange method. First, thioacetamide is used as a sulfur source and zinc stearate is used as a zinc source to synthesize zinc sulfide quantum dots. Then, lead chloride is used as a lead source, and cation exchange is performed with the zinc sulfide quantum dots. The absorption peak of the PbS CQD is controlled by controlling the reaction time of the lead chloride and the zinc sulfide quantum dots. The PbS CQD synthesized by the cation exchange method is dissolved in an octane quantum dot solution at a concentration of 10 mg / ml to obtain an initial quantum dot solution. In the initial quantum dot solution synthesized by this method, the quantum dot PbSCQD is wrapped by oleic acid ligands, and the spacing between the quantum dots is too large, and there is a problem of low mobility. Therefore, it is necessary to perform ligand exchange on it, and replace the long-chain oleic acid ligand with a short-chain halogen such as iodine and bromine single-atom ligands to enhance the electrical properties of the PbS CQD.

[0066] 2) Prepare ligand solution.

[0067] Specifically, PbI2 and PbBr2 are mixed with N,N-dimethylformamide solution to obtain the ligand solution.

[0068] In a specific embodiment, the solid drugs of PbI2 and PbBr2 are weighed by a balance and mixed with a DMF solution, and then fully shaken to dissolve to prepare a ligand solution with a PbI2 and PbBr2 concentration of 0.0267 mmol / ml and 0.0115 mmol / ml, respectively.

[0069] 3) Mixing the initial quantum dot solution with the ligand solution to perform ligand exchange to obtain the quantum dot solution, wherein the quantum dots in the quantum dot solution are wrapped by halogen.

[0070] Specifically, the initial quantum dot solution and the ligand solution are filtered and mixed according to a preset ratio, and fully shaken to perform ligand exchange; the upper layer solution is removed, and n-octane is added, mixed and shaken, and the upper layer liquid is removed; the lower layer solution is centrifuged to remove the solvent to obtain the quantum dot solution.

[0071] In a specific embodiment, the ligand exchange is carried out in a nitrogen atmosphere glove box. Use a syringe and a filter head with a pore size of 0.22 μm to filter and mix the initial quantum dot solution and the ligand solution in a volume ratio of 1: 1, fully shake, and perform ligand exchange. After standing for a period of time, the PbS CQD with iodine and bromine atom ligands is in the lower DMF polar phase, and the n-octane solvent in the upper layer becomes transparent, and the upper solution is removed. Further, in order to reduce the content of residual oleic acid, an equal amount of n-octane is added, mixed and shaken for cleaning, and the upper liquid is removed after stratification, and the cleaning process is repeated twice. Finally, the DMF solution containing PbS CQD in the lower layer is divided into centrifuge tubes, and the solution is removed after centrifugation at 9000r / min for 5min, leaving a precipitate quantum dot solution. The quantum dot PbS CQD in the quantum dot solution is wrapped by iodine and bromine atom ligands, and is placed in a low-pressure drying oven to further remove the residual solvent for standby use.

[0072] Step S12: preparing a quantum dot dispersant using 2,6-bis(aminomethyl)pyridine ligand.

[0073] Specifically, a quaternary dispersion system is prepared, wherein the quaternary dispersion system includes N,N-dimethylformamide, dimethyl sulfoxide, n-butylamine, and 3-pyridinemethylamine; 2,6-bis(aminomethyl)pyridine ligand is dissolved in N,N-dimethylformamide, and the quaternary dispersion system is added to obtain the quantum dot dispersant.

[0074] In one embodiment, a quaternary dispersion system is prepared in advance, the quaternary dispersion system includes N, N-dimethylformamide, dimethyl sulfoxide, n-butylamine, and 3-pyridine methylamine, and in the quaternary dispersion system, the ratio of N, N-dimethylformamide, dimethyl sulfoxide, n-butylamine, and 3-pyridine methylamine is 350ul: 250ul: 370ul: 30ul. 0.01mmol of 2,6-bis(aminomethyl)pyridine ligand is dissolved in 350ul of DMF dispersant, and the existing quaternary dispersion system is added at a concentration of 400mg / ml, and the quantum dot dispersant is obtained after sufficient oscillation and dispersion.

[0075] In the above process, the liquid phase ligand exchange method was used to replace the long-chain oleic acid ligand with a short-chain halogen such as iodine and bromine single-atom ligand. In this process, there are two stages to add new ligand materials, one stage is to add it to the ligand material in the ligand exchange part, and the other stage is to add it to the solvent in the film spin coating part. In comparison, the latter stage is more suitable for two reasons: First, the newly added 2,6-bis (aminomethyl) pyridine ligand itself has a coordination effect with the lead ion, and the original ligand material contains PbI2 and PbBr2 materials. The three will react in advance, which may cause the precursor to denature and lose its function; second, even if the three can coexist, in the process of acting together with PbS CQD in the solution, competition may occur due to different binding forces, resulting in the original passivation design cannot be achieved. In the step of film spin coating, 2,6-bis (aminomethyl) pyridine is added to the solvent, which is expected to perform secondary passivation on the halogen-coated PbS CQD, which has the effect of checking for deficiencies and filling gaps. More importantly, PbS CQDs are more dispersed in liquid environments. Due to the existence of the environmental dielectric constant, the CQDs are spaced widely and the probability of agglomeration is low. However, during the spin coating process, the solvent evaporates quickly, the CQDs accumulate on the substrate, and the spacing decreases rapidly, which can easily cause the fusion of the crystal planes. Therefore, 2,6-bis(aminomethyl)pyridine is more suitable as a component of the spin coating solvent.

[0076] Step S13: adding the quantum dot solution into the quantum dot dispersant to obtain an active layer precursor.

[0077] The quantum dot solution is added into the quantum dot dispersant to obtain an active layer precursor.

[0078] The method of the present application obtains the active layer precursor in the above manner, which more effectively passivates the quantum dots, reduces the surface defects of the quantum dots, suppresses the dark current and thus improves the detection performance of the device.

[0079] Step S14: preparing an active layer based on the active layer precursor, thereby preparing the photodetector.

[0080] For details, please combine Figure 2 , step S14 specifically includes:

[0081] Step S141: preparing a bottom electrode layer.

[0082] In one embodiment, the bottom electrode layer material is indium tin oxide. Specifically, an indium tin oxide film is sputtered on the substrate by magnetron sputtering, and the indium tin oxide film is patterned by laser etching / photolithography / nanoimprinting process to form the bottom electrode layer.

[0083] Step S142: preparing an electron blocking layer on the bottom electrode layer.

[0084] 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. The target material is a Li-doped NiOx target. Specifically, the distance between the target and the substrate is set to 80 cm, and the RF mode sputtering is adopted. Argon gas is introduced to make the chamber pressure about 2.0 Pa, the sputtering power is 200 W, and the sputtering time is 5 minutes, so as to obtain a NiOx film of about 20 nm thickness, thereby forming an electron blocking layer.

[0085] Step S143: preparing a P-type layer on a surface of the electron blocking layer away from the bottom electrode layer.

[0086] The material of the P-type layer is PbS. Specifically, the p-type layer 113 is a PbS quantum dot material with EDT as a ligand and an absorption wavelength of 880nm. In one embodiment, the operation is carried out in a fume hood, and the PbS CQD with an absorption peak of 880nm is dissolved in n-octane to prepare a 40mg / ml quantum dot solution, and the EDT solution (ethylene glycol diamine tetraacetic acid) is dispersed in acetonitrile to prepare a ligand solution with an EDT mass fraction of 0.01%. The solid phase exchange method is adopted, and the spin coating parameters are set to 4000r / min, 20s, first spin-coat a layer of quantum dot solution, and then the ligand solution is added to the film, and it is left to stand for 30s, waiting for the ligand exchange to be complete, and then the surface is washed twice with acetonitrile to obtain a PbS-EDT film of about 20nm thickness, thereby preparing the P-type layer.

[0087] Step S144: using the active layer precursor to prepare the active layer on a surface of the P-type layer away from the bottom electrode layer.

[0088] In one embodiment, the active layer precursor may be spin-coated on a surface of the P-type layer away from the bottom electrode layer by spin coating, thereby forming the active layer.

[0089] Step S145: preparing a sacrificial layer on a surface of the active layer away from the bottom electrode layer.

[0090] The material of the electron transport layer is C 60 The device with active layer is placed on the thermal evaporation instrument, and the film is deposited by thermal evaporation. The C 60 , keeping the evaporation rate at 0.005-0.015 nm / s, prepare a C layer with a thickness of about 15 nm 60 , a sacrificial layer is prepared.

[0091] Step S146: preparing an electron transport layer on a surface of the sacrificial layer away from the bottom electrode layer.

[0092] The material of the electron transport layer is SnO2, and the electron transport layer is prepared by coating on a surface of the sacrificial layer away from the bottom electrode layer by atomic layer deposition. Specifically, the film is coated by atomic layer deposition, with tetrakis(dimethylamino)tin (TDMASn) as the tin source, water as the oxygen source, the tin source temperature is set to 60°C, the substrate temperature is set to 90°C, and the reaction is carried out as fully as possible. After 250 cycles of growth, a SnO2 film with a thickness of about 40nm is obtained, and the electron transport layer is prepared.

[0093] Step S147: preparing a top electrode layer on a surface of the electron transport layer away from the bottom electrode layer.

[0094] The material of the top electrode layer is indium tin oxide. The top electrode is coated using magnetron sputtering JCP500, and the target material is indium-doped tin oxide. The distance between the target and the substrate is set to 80 cm, and DC mode sputtering is used. Argon and oxygen are introduced to make the chamber pressure about 0.5 Pa, where the gas flow ratio of argon to oxygen is 99:1, the sputtering power is set to 100 W, and the sputtering time is 15 minutes. An ITO film with a thickness of about 200 nm is obtained to prepare the top electrode layer, and finally a photodetector is prepared.

[0095] In the photodetector prepared by the method of the present application, the crystal defects exposed by the PbSCQDs are better passivated by the above-mentioned ligand supplementation passivation method, which effectively improves the photoelectric performance of the photodetector. Specifically, the dark current of the device at a detection wavelength of 1550nm is less than 40nA / cm2 at -0.01V and less than 300nA / cm2 at -0.5V. While maintaining a low dark current, the external quantum efficiency EQE can exceed 70%.

[0096] See also Figure 3 , Figure 3 This is a structural schematic diagram of an embodiment of the photoelectric detector of the present application. The photoelectric detector of the present application is prepared by the method described above, and the photoelectric 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, an electron transport layer 116, and a top electrode layer 117.

[0097] Among them, the active layer 114 is a PbS CQD layer, which can absorb the energy of photons under 1550nm light irradiation and generate light signals. The electron blocking layer 112, the p-type layer 113, the active layer 114, the electron transport layer 115, and the electron transport layer 116 form an ohmic contact between the bottom electrode layer 111 and the top electrode layer 117. Among them, the electron blocking layer 112, the p-type layer 113, the active layer 114, the electron transport layer 115, and the electron transport layer 116 form a pin structure as a whole. Under 1550nm light irradiation, the active layer 114 will generate electrons and vacancies, and the electrons will go along the electron transport layer 115 to the electron transport 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 and the electron transport layer 116 form a pn junction (light-emitting diode structure), and 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 exhausted, the photocurrent is maximum, and 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.

[0098] 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.

[0099] The material of the electron transport layer 116 is SnO 2 .

[0100] The material of the electron transport layer 115 is C 60 .

[0101] The material of the p-type layer 113 is PbS. Specifically, the p-type layer 113 is a PbS quantum dot material with EDT as a ligand and an absorption wavelength of 880 nm.

[0102] The material of the electron blocking layer 112 is NiOX.

[0103] 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.

[0104] A ligand supplementary passivation method is introduced into the active layer 114, and the crystal defects exposed by the PbS QDs are better passivated, which effectively improves the photoelectric performance of the photodetector. Specifically, the dark current of the device at a detection wavelength of 1550nm is less than 40nA / cm2 at -0.01V and less than 300nA / cm2 at -0.5V. While maintaining a low dark current, the external quantum efficiency EQE can exceed 70%.

[0105] 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.

[0106] 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.

[0107] 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.

[0108] 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.

[0109] 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.

[0110] 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 photoelectric detector, characterized in that: include: preparing a quantum dot solution, wherein the quantum dots in the quantum dot solution are coated with halogen; The quantum dot dispersant was prepared using 2,6-bis(aminomethyl)pyridine ligand; adding the quantum dot solution into the quantum dot dispersant to obtain an active layer precursor; An active layer is prepared based on the active layer precursor, thereby preparing the photodetector.

2. The preparation method according to claim 1, characterized in that: The steps of preparing a quantum dot solution include: preparing an initial quantum dot solution, in which quantum dots are encapsulated by oleic acid ligands; Prepare ligand solution; The initial quantum dot solution is mixed with the ligand solution to perform ligand exchange to obtain the quantum dot solution, wherein the quantum dots in the quantum dot solution are wrapped by halogen.

3. The preparation method according to claim 2, characterized in that: The steps of preparing an initial quantum dot solution include: Synthesis of zinc sulfide quantum dots using thioacetamide and zinc stearate; Lead chloride and the zinc sulfide quantum dots are used to carry out cation exchange, the reaction time of the lead chloride and the zinc sulfide quantum dots is controlled, and the zinc sulfide quantum dots are added into n-octane, so as to obtain the initial quantum dot solution.

4. The preparation method according to claim 2, characterized in that: The steps of preparing the ligand solution include: PbI2 and PbBr2 are mixed with N,N-dimethylformamide solution to obtain the ligand solution.

5. The preparation method according to claim 2, characterized in that: The step of mixing the initial quantum dot solution with the ligand solution and performing ligand exchange to obtain the quantum dot solution comprises: Filtering and mixing the initial quantum dot solution and the ligand solution according to a preset ratio, and shaking them sufficiently to perform ligand exchange; Remove the upper solution, add n-octane, mix and shake, and remove the upper liquid; The lower layer solution is centrifuged to remove the solvent to obtain the quantum dot solution.

6. The preparation method according to any one of claims 1 to 5, characterized in that: The step of preparing a quantum dot dispersant using a 2,6-bis(aminomethyl)pyridine ligand comprises: preparing a quaternary dispersion system, wherein the quaternary dispersion system comprises N,N-dimethylformamide, dimethyl sulfoxide, n-butylamine, and 3-pyridinemethylamine; The quantum dot dispersant is obtained by dissolving 2,6-bis(aminomethyl)pyridine ligand in N,N-dimethylformamide and adding a quaternary dispersion system.

7. The preparation method according to any one of claims 1 to 6, characterized in that: The steps of preparing the active layer based on the active layer precursor, thereby preparing the photodetector 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 a sacrificial layer on a surface of the active layer away from the bottom electrode layer; Preparing an electron transport layer on a surface of the sacrificial layer away from the bottom electrode layer; A top electrode layer is prepared on a surface of the electron transport 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 C 60 ; The material of the electron transport 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 sacrificial layer on a surface of the active layer away from the bottom electrode layer comprises: The film is deposited by thermal evaporation, and the C 60 , preparing a sacrificial layer on a surface of the active layer away from the bottom electrode layer; The step of preparing an electron transport layer on a surface of the sacrificial layer away from the bottom electrode layer comprises: The electron transport layer is prepared by coating a surface of the sacrificial layer away from the bottom electrode layer in an atomic layer deposition manner.

10. A photoelectric detector, characterized in that: The photoelectric detector is prepared by the photoelectric detector preparation method described in any one of claims 1 to 9.

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