CN-121160321-B - Quantum dot material and preparation method thereof, perovskite solar cell and preparation method thereof

CN121160321BCN 121160321 BCN121160321 BCN 121160321BCN-121160321-B

Abstract

The disclosure provides a quantum dot material and a preparation method thereof, and a perovskite solar cell and a preparation method thereof. The quantum dot material comprises a quantum dot core material and a ligand connected to the quantum dot core material, wherein the quantum dot core material is silver selenide quantum dots, and the ligand comprises cysteine. The quantum dot material can reduce defects in the perovskite solar cell and improve short-circuit current of the perovskite solar cell under the condition that the optical band gap of the perovskite solar cell is not affected basically.

Inventors

CHEN CHONG
YANG DONG
JIN MENGQI

Assignees

中国科学院合肥物质科学研究院

Dates

Publication Date: 20260512
Application Date: 20251120

Claims (5)

1. A perovskite solar cell, comprising: A first electrode; An electron transport layer disposed on the first electrode; The perovskite layer is arranged on one side of the electron transport layer, which is far away from the first electrode; a second electrode disposed on a side of the perovskite layer remote from the electron transport layer; The electron transport layer comprises a tin oxide film and a quantum dot material arranged between the tin oxide film and the perovskite layer, the quantum dot material is in contact with the tin oxide film and the perovskite layer, the quantum dot material comprises a quantum dot core material and a ligand connected with the quantum dot core material, the quantum dot core material is silver selenide quantum dots, and the ligand comprises cysteine; The preparation method of the quantum dot material comprises the following steps: The preparation method comprises the steps of dispersing silver salt and phosphine compound in a second organic solvent to form silver salt solution, heating the silver salt solution to more than 150 ℃ in the environment of protective gas, mixing a selenium source with the heated silver salt solution, then cooling to form a product stock solution, separating a solid phase product in the product stock solution, and drying the solid phase product, wherein the quantum dot raw material comprises a quantum dot core material and a ligand connected with the quantum dot core material, the quantum dot core material is silver selenide quantum dots, the ligand comprises phosphine compound, and the phosphine compound is selected from trialkylphosphine; Dispersing the quantum dot raw material in a first organic solvent to form a quantum dot raw material dispersion liquid, wherein the mass concentration of the quantum dot material in the quantum dot dispersion liquid is 0.01 mg/mL-0.05 mg/mL, cysteine is mixed with the quantum dot raw material dispersion liquid, the mass ratio of the quantum dot raw material to the cysteine is (2-5): 1, and the ligand in the quantum dot raw material is replaced by the cysteine to form the quantum dot material.
2. The perovskite solar cell of claim 1, wherein in the electron transport layer, the quantum dot material is attached to the tin oxide film surface and at least a portion of the electron transport layer is in direct contact with the perovskite layer.
3. The perovskite solar cell according to claim 1, wherein the thickness of the tin oxide thin film is 30nm to 50nm, and/or, The thickness of the perovskite layer is 400-500 nm.
4. The perovskite solar cell of claim 1, wherein the second organic solvent comprises one or more of octadecene, oleylamine, and oleic acid; after separating the solid-phase product in the product stock solution and before drying, the method further comprises the step of removing the second organic solvent attached to the surface of the solid-phase product.
5. The preparation method of the perovskite solar cell is characterized by comprising the following steps of: Forming a tin oxide film on the first electrode; Coating a quantum dot dispersion liquid on the surface of the tin oxide film, and then carrying out annealing treatment, wherein the quantum dot dispersion liquid contains a quantum dot material, the quantum dot material comprises a quantum dot core material and a ligand connected with the quantum dot core material, the quantum dot core material is silver selenide quantum dots, and the ligand comprises cysteine; the preparation method of the quantum dot material comprises the following steps: The preparation method comprises the steps of dispersing silver salt and phosphine compound in a second organic solvent to form silver salt solution, heating the silver salt solution to more than 150 ℃ in the environment of protective gas, mixing a selenium source with the heated silver salt solution, then cooling to form a product stock solution, separating a solid phase product in the product stock solution, and drying the solid phase product, wherein the quantum dot raw material comprises a quantum dot core material and a ligand connected with the quantum dot core material, the quantum dot core material is silver selenide quantum dots, the ligand comprises phosphine compound, and the phosphine compound is selected from trialkylphosphine; Dispersing the quantum dot raw material in a first organic solvent to form a quantum dot raw material dispersion liquid, wherein in the quantum dot dispersion liquid, the mass concentration of the quantum dot material is 0.01 mg/mL-0.05 mg/mL, cysteine is mixed with the quantum dot raw material dispersion liquid, the mass ratio of the quantum dot raw material to the cysteine is (2-5): 1, and the ligand in the quantum dot raw material is replaced by the cysteine to form the quantum dot material; forming a perovskite layer on the tin oxide film, and A second electrode is formed on the perovskite layer.

Description

Quantum dot material and preparation method thereof, perovskite solar cell and preparation method thereof Technical Field The invention relates to the technical field of perovskite solar cells, in particular to a quantum dot material and a preparation method thereof, and a perovskite solar cell and a preparation method thereof. Background Perovskite solar cells are a type of photovoltaic device that employs perovskite materials as the semiconductor light absorbing layer. Perovskite solar cells have the advantages of higher conversion efficiency, lower manufacturing cost, wider application range and the like, and are widely concerned. Tin oxide has higher permeability to visible light and higher electron mobility, and also has better chemical stability, and can be used as an electron transport layer material in a perovskite solar cell. However, the interface between the tin oxide material and the perovskite material has a high concentration of defects. This negatively affects the performance of perovskite solar cells employing tin oxide materials as electron transport layers, limiting the further use of tin oxide in perovskite solar cells. Disclosure of Invention Based on this, it is necessary to provide a quantum dot material against the problems in the background art described above. When the quantum dot material is applied to a perovskite solar cell, oxygen vacancy defects in a tin oxide material and interface defects between tin oxide and the perovskite material can be passivated, and stress of a tin oxide film and a perovskite layer can be released, so that the performance of the perovskite solar cell is improved. In a first aspect, the present disclosure provides a quantum dot material comprising a quantum dot core material and a ligand attached to the quantum dot core material, the quantum dot core material being silver selenide quantum dots, the ligand comprising cysteine. In a second aspect, the present disclosure provides a method of preparing a quantum dot material, comprising the steps of: Obtaining a quantum dot raw material, wherein the quantum dot raw material comprises a quantum dot nuclear material and a ligand connected to the quantum dot nuclear material, the quantum dot nuclear material is silver selenide quantum dots, and the ligand comprises a phosphine compound; Dispersing the quantum dot raw material in a first organic solvent to form a quantum dot raw material dispersion liquid, mixing cysteine with the quantum dot raw material dispersion liquid, and replacing a ligand in the quantum dot raw material with cysteine to form the quantum dot material. In some embodiments of the present disclosure, the step of obtaining a quantum dot feedstock comprises: Dispersing silver salt and phosphine compound in a second organic solvent to form silver salt solution, and heating the silver salt solution to more than 150 ℃ under the environment of protective gas; mixing a selenium source with the heated silver salt solution, then cooling to form a product stock solution, and And separating a solid-phase product in the product stock solution, and drying the solid-phase product. In some embodiments of the present disclosure, the second organic solvent comprises one or more of octadecene, oleylamine, and oleic acid; after separating the solid-phase product in the product stock solution and before drying, the method further comprises the step of removing the second organic solvent attached to the surface of the solid-phase product. In some embodiments of the present disclosure, in the step of mixing cysteine with the quantum dot raw material dispersion, the mass ratio of the quantum dot raw material to cysteine is (2-5): 1. In a third aspect, the present disclosure provides a perovskite solar cell comprising: A first electrode; An electron transport layer disposed on the first electrode; The perovskite layer is arranged on one side of the electron transport layer, which is far away from the first electrode; a second electrode disposed on a side of the perovskite layer remote from the electron transport layer; The electron transport layer comprises a tin oxide film and a quantum dot material arranged between the tin oxide film and the perovskite layer, the quantum dot material is in contact with the tin oxide film and the perovskite layer, the quantum dot material comprises the quantum dot material according to any embodiment, or the quantum dot material comprises the quantum dot material prepared by the preparation method according to any embodiment. In some embodiments of the present disclosure, in the electron transport layer, the quantum dot material is attached to the tin oxide film surface, and at least a portion of the electron transport layer is in direct contact with the perovskite layer. In some embodiments of the present disclosure, the tin oxide film has a thickness of 30nm to 50nm, and/or, The thickness of the perovskite layer is 400-500 nm. In a fourth aspect, the present disclosure provides