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CN-121985670-A - AgBiS based on core-shell structure2@Bi2S3Quantum dot photoelectric detector and preparation method thereof

CN121985670ACN 121985670 ACN121985670 ACN 121985670ACN-121985670-A

Abstract

The invention is suitable for the technical field of photoelectric devices, and provides a photoelectric detector based on AgBiS 2 @Bi 2 S 3 quantum dots with a core-shell structure and a preparation method thereof. The core-shell quantum dots are synthesized step by a thermal injection method, a Bi 2 S 3 shell layer and an AgBiS 2 core form a quasi-II heterojunction, energy band matching is beneficial to carrier separation and transmission, and meanwhile, surface defects are effectively passivated and environmental corrosion is isolated. The photoelectric detector has the advantages of low dark current, high detection rate and good air stability, and has good application prospect in the photoelectric detection field.

Inventors

  • DING NAN
  • YAO MINGYU
  • XU WEN
  • DONG BIN

Assignees

  • 大连民族大学

Dates

Publication Date
20260505
Application Date
20260129

Claims (9)

  1. 1. Photoelectric detector based on nuclear shell structure AgBiS 2 @Bi 2 S 3 quantum dot, its characterized in that, photoelectric detector includes from bottom to top in proper order: the substrate layer adopts FTO transparent conductive glass; An electron transport layer made of SnO 2 material; the quantum dot photosensitive active layer consists of a plurality of layers of stacked core-shell structure AgBiS 2 @Bi 2 S 3 quantum dots; A hole transport layer made of a spira-ome tad material; And the top electrode layer adopts an Ag electrode.
  2. 2. The photoelectric detector based on the core-shell structure AgBiS 2 @Bi 2 S 3 quantum dot according to claim 1, wherein in the AgBiS 2 @Bi 2 S 3 quantum dot, the conduction band bottom of a Bi 2 S 3 shell layer is lower than or equal to the conduction band bottom of an AgBiS 2 core, and the valence band top of the shell layer is lower than the valence band top of the AgBiS 2 core.
  3. 3. The photoelectric detector based on the core-shell structure AgBiS 2 @Bi 2 S 3 quantum dots, according to claim 1, wherein the quantum dot photosensitive active layer is synthesized by AgBiS 2 @Bi 2 S 3 quantum dots through a thermal injection method.
  4. 4. The preparation method of the photoelectric detector based on the core-shell structure AgBiS 2 @Bi 2 S 3 quantum dot is based on the photoelectric detector based on the core-shell structure AgBiS 2 @Bi 2 S 3 quantum dot, and is characterized by comprising the following steps of: step 1, cleaning a substrate layer; Step 2, spin coating an electron transport layer; Step3, spin coating of core-shell quantum dots; Step 4, spin coating a hole transport layer; and 5, evaporating a top electrode layer.
  5. 5. The preparation method of the photoelectric detector based on the core-shell structure AgBiS 2 @Bi 2 S 3 quantum dot, which is disclosed in claim 4, is characterized in that the specific steps of the step 1 are as follows: The FTO transparent conductive glass is subjected to ultrasonic treatment in an alcohol environment of 20min, then ultrasonic treatment in an acetone environment of 20min, finally ultrasonic treatment in a deionized water environment of 20min, and then the glass is put into an oven for drying.
  6. 6. The preparation method of the photoelectric detector based on the core-shell structure AgBiS 2 @Bi 2 S 3 quantum dot, which is disclosed in claim 5, is characterized in that the specific steps of the step2 are as follows: And spin-coating SnO 2 nanometer particle solution on the FTO transparent conductive glass at a rotation speed of 5000 rpm for 30 s, and annealing at 150 ℃ for 30min to form an electron transport layer.
  7. 7. The method for preparing the photoelectric detector based on the core-shell structure AgBiS 2 @Bi 2 S 3 quantum dot according to claim 6, wherein the specific steps of the step 3 are as follows: Spin-coating AgBiS 2 @Bi 2 S 3 quantum dot dispersion liquid on the electron transport layer at 2000 rpm for 30 s, annealing for 10 min, dripping solution containing short ligand for in-situ ligand exchange, removing long-chain organic ligand to densify the quantum dot film, then flushing with methanol solution, repeating the spin-coating-exchange-cleaning step for 3 times to form the quantum dot photosensitive active layer.
  8. 8. The method for preparing the photoelectric detector based on the core-shell structure AgBiS 2 @Bi 2 S 3 quantum dot according to claim 4, wherein the specific steps of the step 4 are as follows: The formulated Spiro-OMeTAD solution was spin coated onto the quantum dot photoactive layer at a rate of 3000 rpm for 30 s.
  9. 9. The method for preparing a core-shell structure AgBiS 2 @Bi 2 S 3 quantum dot-based photodetector according to claim 4, wherein in step 5, ag is used as a top electrode layer by vacuum evaporation.

Description

Photoelectric detector based on AgBiS 2@Bi2S3 quantum dots with core-shell structure and preparation method thereof Technical Field The invention belongs to the technical field of photoelectric devices, and particularly relates to a photoelectric detector based on a core-shell structure AgBiS 2@Bi2S3 quantum dot and a preparation method thereof. Background The AgBiS 2 quantum dot is regarded as an ideal material of a next-generation thin film photoelectric device because of high light absorption coefficient, environment friendliness and rich element reserves. Typical AgBiS 2 devices generally employ a "sandwich" structure that includes a conductive substrate, an electron transport layer, an AgBiS 2 active layer, a hole transport layer, and a top electrode. However, the existing AgBiS 2 quantum dot film has the problems of high surface defect density, more deep energy level defects at grain boundaries and the like, so that serious non-radiative recombination and high dark current are caused, and the efficiency and detection performance of the device are limited. The current ligand exchange method can improve carrier mobility, but cannot completely eliminate surface structural defects, and has poor device stability. Disclosure of Invention The embodiment of the invention aims to provide a photoelectric detector based on a core-shell structure AgBiS 2@Bi2S3 quantum dot and a preparation method thereof, and aims to solve the problems in the background technology. The embodiment of the invention is realized in such a way that the photoelectric detector based on the AgBiS 2@Bi2S3 quantum dot with the core-shell structure sequentially comprises the following components from bottom to top: the substrate layer adopts FTO transparent conductive glass; An electron transport layer made of SnO 2 material; the quantum dot photosensitive active layer consists of a plurality of layers of stacked core-shell structure AgBiS 2@Bi2S3 quantum dots; A hole transport layer made of a spira-ome tad material; And the top electrode layer adopts an Ag electrode. According to a further technical scheme, in the AgBiS 2@Bi2S3 quantum dot, the conduction band bottom (CBM) of the Bi 2S3 shell layer is lower than or equal to the conduction band bottom of the AgBiS 2 core, and the valence band top (VBM) of the shell layer is lower than the valence band top of the AgBiS 2 core. According to a further technical scheme, the quantum dot photoactive layer is synthesized by AgBiS 2@Bi2S3 quantum dots through a hot injection method. Another object of the embodiment of the invention is to provide a method for preparing a photoelectric detector based on a core-shell structure AgBiS 2@Bi2S3 quantum dot, based on the photoelectric detector, comprising the following steps: step 1, cleaning a substrate layer; Step 2, spin coating an electron transport layer; Step3, spin coating of core-shell quantum dots; Step 4, spin coating a hole transport layer; and 5, evaporating a top electrode layer. According to a further technical scheme, the specific steps of the step 1 are as follows: The FTO transparent conductive glass is subjected to ultrasonic treatment in an alcohol environment of 20min, then ultrasonic treatment in an acetone environment of 20min, finally ultrasonic treatment in a deionized water environment of 20min, and then the glass is put into an oven for drying. According to a further technical scheme, the specific steps of the step 2 are as follows: And spin-coating SnO 2 nanometer particle solution on the FTO transparent conductive glass at a rotation speed of 5000 rpm for 30 s, and annealing at 150 ℃ for 30min to form an electron transport layer. According to a further technical scheme, the specific steps of the step 3 are as follows: Spin-coating AgBiS 2@Bi2S3 quantum dot dispersion liquid on the electron transport layer at 2000 rpm for 30 s, annealing for 10 min, dripping solution containing short ligand (tetramethyl ammonium iodide TMAI) for in-situ ligand exchange, removing long-chain organic ligand, densifying the quantum dot film, washing with methanol solution, repeating the spin-coating-exchange-cleaning step for 3 times to form the quantum dot photosensitive active layer. According to a further technical scheme, the specific steps of the step 4 are as follows: The formulated Spiro-OMeTAD solution was spin coated onto the quantum dot photoactive layer at a rate of 3000 rpm for 30 s. In a further technical solution, in the step 5, ag is used as the top electrode layer by vacuum evaporation. The photoelectric detector based on the AgBiS 2@Bi2S3 quantum dot with the core-shell structure and the preparation method thereof provided by the embodiment of the invention have the following beneficial effects: (1) The dark current is obviously reduced, the detection performance is improved, the Bi 2S3 shell layer effectively passivates the surface defect of the AgBiS 2 quantum dot core, the dark current of the device is reduced by about 1 order of