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CN-122003074-A - Quantum dot detector preparation method based on one-step synthesis method

CN122003074ACN 122003074 ACN122003074 ACN 122003074ACN-122003074-A

Abstract

The application discloses a quantum dot detector preparation method based on a one-step synthesis method, and belongs to the technical field of infrared detectors. The method comprises providing a substrate, preparing a bottom electrode on the substrate, preparing a hole transport layer on the bottom electrode, wherein the hole transport layer comprises NiOx film and PbS-EDT film, preparing a quantum dot light absorption layer comprising 1550nmPbS CQD on the hole transport layer by one-step synthesis method, and preparing an electron transport layer comprising C 60 film and PbS-EDT film on the quantum dot light absorption layer And preparing a top electrode on the electron transport layer. According to the method, after 1550nm PbS colloid quantum dots are synthesized by adopting a thermal injection method, the quantum dot cleaning step is omitted, liquid phase exchange is directly carried out, water oxygen introduction and ligand damage are avoided from the root, the process is simplified, the surface stability of the quantum dots is ensured, and the performance and the large-scale production potential of the infrared detector are improved.

Inventors

  • GAO LIANG
  • LIU YINING
  • SHI HUILEI
  • LIU JING
  • TANG JIANG

Assignees

  • 华中科技大学
  • 湖北光谷实验室

Dates

Publication Date
20260508
Application Date
20251230

Claims (10)

  1. 1. The preparation method of the quantum dot detector based on the one-step synthesis method is characterized by comprising the following steps of: Providing a substrate; Preparing a bottom electrode on the substrate; Preparing a hole transport layer on the bottom electrode, wherein the hole transport layer comprises a NiOx film and a PbS-EDT film; Preparing a quantum dot light absorption layer on the hole transport layer by adopting a one-step synthesis method, wherein the quantum dot light absorption layer comprises 1550nmPbS CQDs; Preparing an electron transport layer on the quantum dot light absorption layer, wherein the electron transport layer comprises a C 60 film and A film; A top electrode is prepared on the electron transport layer.
  2. 2. The method of fabricating a quantum dot detector based on a one-step synthesis process according to claim 1, wherein the fabrication of the bottom electrode comprises: Selected to be doped with Sn As a target material; the DC power supply is used as an excitation source, sputtering air pressure of 0.3Pa is adopted, argon is used as ionized gas, and meanwhile, the sputtering power is reduced to 33W, so that the bottom electrode is obtained.
  3. 3. The method for fabricating a quantum dot detector based on a one-step synthesis method according to claim 2, wherein the fabrication of the hole transport layer includes a NiOx thin film fabrication and a PbS-EDT thin film fabrication, the NiOx thin film fabrication being a magnetron sputtering process fabrication method comprising: using Li doped NiOx as a target; Placing the substrate in a vacuum chamber and vacuumizing until the basic pressure is greater than Pa, controlling sputtering air pressure to be 3.4Pa by adjusting air flow, introducing 100sccm argon as ionization gas to provide glow discharge, and adopting a 200W radio frequency power supply as an excitation source to obtain the NiOx film.
  4. 4. The method of preparing a quantum dot detector based on one-step synthesis as claimed in claim 3, wherein the PbS-EDT film preparation comprises: PbO is used as a lead source precursor, and PbS CQDs are prepared by a trimethylsilyl sulfide heat injection method to obtain the OA coated CQDs; CQDs coated with OA at 20mg Dissolving in n-octane, spin-coating on the surface of a NiOx film at 2500rpm, performing aftertreatment for 30s by using an EDT acetonitrile solution with the volume fraction of 0.02%, replacing oleic acid ligand with the EDT ligand, finally washing the surface twice by using the acetonitrile solution, and repeating the operation twice to obtain the PbS-EDT film.
  5. 5. The method of preparing a quantum dot detector based on one-step synthesis according to claim 4, wherein the preparation of the quantum dot light absorbing layer comprises PbS quantum dot synthesis, ligand exchange and 1550nmPbS CQD thin film preparation, the PbS quantum dot synthesis comprising: and synthesizing PbS colloid quantum dots with absorption peaks at 1550nm by a thermal injection method to obtain quantum dot stock solution.
  6. 6. The method of preparing a quantum dot detector based on one-step synthesis according to claim 5, wherein the ligand exchange comprises: and directly mixing the synthesized quantum dot stock solution with the exchange solution of the iodine-bromine ligand to exchange the liquid ligand.
  7. 7. The method of one-step synthesis method according to claim 6, wherein the preparation of 1550nmPbS CQD thin film comprises preparing dispersant with a ratio of DMF to DMSO to BTA to 3-aminopyridine=350 to 250 to 370 to 30, preparing 400mg/ml PbS colloidal quantum dot ink, spin-coating on device and annealing at 90 ℃ for 15min, and obtaining 1550nmPbS CQD thin film.
  8. 8. The method for preparing a quantum dot detector based on one-step synthesis according to claim 7, wherein the preparing the electron transport layer comprises Film preparation and C 60 film preparation, said The film is prepared by adopting an atomic layer deposition method.
  9. 9. The method for preparing a quantum dot detector based on a one-step synthesis method according to claim 8, wherein the preparation of the C 60 film adopts a thermal evaporation process.
  10. 10. The quantum dot detector based on the one-step synthesis method is characterized by sequentially comprising a substrate, a bottom electrode, a hole transport layer, a quantum dot light absorption layer, an electron transport layer and a top electrode from bottom to top.

Description

Quantum dot detector preparation method based on one-step synthesis method Technical Field The application belongs to the technical field of infrared detectors, and particularly relates to a quantum dot detector preparation method based on a one-step synthesis method. Background The PbS colloid quantum dot has the outstanding advantages of solution processability, adjustable band gap (near infrared to middle infrared band response is realized through quantum size effect), low raw material cost, good compatibility with flexible substrates and the like, and becomes one of core sensitive materials of a new generation of infrared detectors. Compared with the traditional inorganic semiconductor infrared detector (such as InGaAs, hgCdTe), the PbS colloid quantum dot infrared detector does not need complicated epitaxial growth equipment, can be prepared by low-cost processes such as spin coating, knife coating and the like, and has great application potential in a large-scale and lightweight infrared detection system. In the preparation flow of the traditional PbS colloid quantum dot infrared detector, synthesis and post-treatment of PbS quantum dots are key links for determining the performance of the device. At present, the common synthesis process of PbS quantum dots in industry uses oleic acid as ligand and octadecene as solvent, and generates PbS quantum dots through high-temperature injection reaction of precursors (such as lead acetate and hexamethyldisilazane), after synthesis, in order to remove unreacted precursors, redundant ligands and solvent impurities remained in the system, usually antisolvent precipitation-cleaning steps are needed, namely, polar antisolvents such as isopropanol, acetone, ethanol and the like are added into reaction liquid to cause precipitation of PbS quantum dots due to reduced solubility, then the quantum dots are collected through centrifugal separation, and repeatedly washed by antisolvent, finally purified PbS quantum dot solid or redispersed quantum dot solution is obtained, and then the solution is used for subsequent ligand exchange (such as iodine ion passivation) and device preparation. In the existing preparation process of the PbS quantum dot infrared detector, a series of key problems are caused by a synthesized antisolvent precipitation-cleaning step, wherein in the step, trace water remained by antisolvent (such as isopropanol, acetone and ethanol) and water and oxygen in an operation environment inevitably invade the surface of the PbS quantum dot, so that surface hydroxylation and hydrogen bond water adsorption of the quantum dot occur, epitaxial fusion is initiated in subsequent processing, an interband trap state is generated, carrier mobility is reduced, trap state density is increased, meanwhile, the original oleic acid ligand coordination structure on the surface of the quantum dot is damaged by the strong polarity of the antisolvent, ligand is fallen to form surface defects, the performance of the quantum dot is further deteriorated, and the existing PbS quantum dot infrared detector has the problems of higher process complexity, lower equipment cost, low efficiency, poor performance and the like. Disclosure of Invention The present application aims to solve at least one of the technical problems existing in the prior art. Therefore, the application provides a preparation method of a quantum dot detector based on a one-step synthesis method, which omits a quantum dot cleaning step after a 1550nm PbS colloid quantum dot is synthesized by adopting a thermal injection method, directly performs liquid phase exchange, radically avoids water oxygen introduction and ligand damage, ensures the surface stability of the quantum dot while simplifying the process, and improves the performance and the large-scale production potential of the infrared detector. In a first aspect, the present application provides a method for preparing a quantum dot detector based on a one-step synthesis method, the method comprising: Providing a substrate; Preparing a bottom electrode on the substrate; Preparing a hole transport layer on the bottom electrode, wherein the hole transport layer comprises a NiOx film and a PbS-EDT film; preparing a quantum dot light absorption layer on the hole transport layer by adopting a one-step synthesis method, wherein the quantum dot light absorption layer comprises 1550nmPbS CQD; Preparing an electron transport layer on the quantum dot light absorption layer, wherein the electron transport layer comprises a C 60 film and A film; A top electrode is prepared on the electron transport layer. According to one embodiment of the present application, the preparation of the bottom electrode includes: selected to be doped with Sn As a target material; the DC power supply is used as an excitation source, sputtering air pressure of 0.3Pa is adopted, argon is used as ionized gas, and meanwhile, the sputtering power is reduced to 33W, so that the bottom electrode