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CN-112993173-B - Method for improving photoelectric conversion efficiency and stability of perovskite solar device

CN112993173BCN 112993173 BCN112993173 BCN 112993173BCN-112993173-B

Abstract

The invention belongs to a method for improving photoelectric conversion efficiency and stability of a device, and particularly relates to a method for reducing defect density and surface potential of an organic-inorganic hybrid perovskite film by utilizing an N-doped condensed ring passivating agent through pi-Pb 2+ interaction, bending an energy band of a perovskite material and improving charge capture efficiency. The method comprises the steps of adding an additive into an antisolvent in the process of preparing an organic-inorganic hybrid perovskite film, and attaching and aggregating on the surface of the formed organic-inorganic hybrid perovskite film. According to the invention, the N-doped condensed ring organic micromolecules are introduced into the perovskite thin film, so that the defects of the perovskite thin film are effectively passivated, the stability of the thin film and a corresponding device is improved, and the adopted materials are low in cost and easy to realize in process.

Inventors

  • ZHOU ZHONGMIN
  • ZHU MINGZHE
  • LI RUITAO
  • ZHANG LINBAO
  • WEN LIRONG

Assignees

  • 青岛科技大学

Dates

Publication Date
20260512
Application Date
20210508

Claims (8)

  1. 1. A method for improving photoelectric conversion efficiency and stability of a perovskite solar device by utilizing pi-Pb 2+ interaction is characterized in that an additive is added into an antisolvent in the process of preparing an organic-inorganic hybrid perovskite film, and the additive is attached and aggregated on the surface of the formed organic-inorganic hybrid perovskite film, wherein the chemical name of the additive is 1- (4-bromophenyl) -6, 7-diphenylimidazo [5,1,2-cd ] indolizine, which is PDPII for short.
  2. 2. The method for improving photoelectric conversion efficiency and stability of a perovskite solar device using pi-Pb 2+ interaction according to claim 1, wherein the concentration of defects and surface potential of an organic-inorganic hybrid perovskite thin film are reduced, and the energy band of a perovskite material is bent, thereby improving charge extraction efficiency.
  3. 3. The method for improving the photoelectric conversion efficiency and the stability of a perovskite solar device by utilizing pi-Pb 2+ interaction according to claim 1 or 2, wherein the molar ratio concentration of PDPII in anti-solvent chlorobenzene is 1 mmol/L.
  4. 4. The method for improving photoelectric conversion efficiency and stability of a perovskite solar device by utilizing pi-Pb 2+ interaction according to claim 1 or 2, wherein after the organic-inorganic hybrid perovskite precursor is spin-coated for a period of time, chlorobenzene dissolved with an additive is sprayed on a film, and then the additive is attached and aggregated on the surface of the film, wherein the solvent of the precursor solution is a mixture of N, N-dimethylformamide and dimethyl sulfoxide.
  5. 5. The method for improving the photoelectric conversion efficiency and the stability of a perovskite solar device using pi-Pb 2+ interaction according to claim 2, wherein the heat treatment temperature of the thin film is 100 o C.
  6. 6. The method for improving photoelectric conversion efficiency and stability of a perovskite solar device by utilizing pi-Pb 2+ interaction according to claim 1 or 2, wherein the organic-inorganic hybrid perovskite structure of the organic-inorganic hybrid perovskite thin film is ABX 3 , A is an alloy containing methylamine ions, formamidine ions and cesium ions, B is one or two of Pb metal ions and Sn metal ions, and X is one or two or more of I, br and Cl ions.
  7. 7. An organic-inorganic hybrid perovskite thin film prepared according to the method of claim 1, wherein the organic-inorganic hybrid perovskite thin film doped with PDPII is prepared according to the method of claim 1.
  8. 8. Use of the thin film according to claim 7, wherein the doped PDPII organic-inorganic hybrid perovskite thin film is used in solar cells to improve photoelectric conversion efficiency and stability.

Description

Method for improving photoelectric conversion efficiency and stability of perovskite solar device Technical Field The invention belongs to a method for improving photoelectric conversion efficiency and stability of a perovskite battery device, and particularly relates to a method for reducing defect concentration and surface potential of an organic-inorganic hybrid perovskite thin film by utilizing an N-hetero condensed ring passivating agent through pi-Pb 2+ interaction, bending an energy band of a perovskite material and improving charge extraction efficiency. Background The metal halide perovskite material has the characteristics of high light absorption coefficient, adjustable forbidden bandwidth and longer carrier diffusion length. The material has a photoelectric effect and converts light energy into electric energy. The solar cell device is hopefully a reliable energy supply device. In recent years, a great deal of research has been devoted to perovskite batteries, increasing the photoelectric conversion efficiency from 3.8% in 2009 to 25.5% in 2020, and thus becoming a powerful competitor to the photovoltaic field. According to Schockley-Queisser limit, for single perovskite solar cells, the theoretical highest photoelectric efficiency is about 30%, so that a certain efficiency improvement space is still available. However, perovskite materials have more inherent defects, and the interface of different materials in the device often has the phenomenon of energy band or energy level mismatch, so that a large amount of charge recombination and low-efficiency charge capture exist in the battery, and the development of the perovskite battery is limited. A variety of strategies have been developed today to mitigate the above-mentioned disadvantages. Chemical doping is considered as an effective means, and not only can the Fermi level position be regulated, but also the charge transmission capacity can be improved, so that a series of high-efficiency devices are prepared. For example, PCBM is commonly used as an electron transport layer, but Wu et al introduce it into FA 0.85MA0.15Pb(I0.85Br0.15)3 via an antisolvent, forming a graded heterojunction, while improving photoelectron collection capability while reducing charge recombination losses. In addition, the CuI-thiourea complex is used for passivating trap states in MAPbI xCl3-x perovskite and extending a dissipation area of an intrinsic heterojunction, so that hole transmission performance of the device is improved, and charge recombination is reduced. Recently, the Huang group of topics doped F4TCNQ into MAPbI 3 changed the work function of perovskite materials, as well as improved device hole transport properties and thus device performance. In view of the work reported above, we developed and synthesized a new small organic molecule. The additive reduces the surface potential of the perovskite film, improves work function, induces energy band bending, promotes hole extraction and reduces charge recombination at an interface. Disclosure of Invention The invention aims to provide a method for improving photoelectric conversion efficiency and stability of a perovskite solar device. In order to achieve the above purpose, the invention adopts the technical scheme that: After spin coating for a period of time, the organic-inorganic hybrid perovskite precursor is sprayed with chlorobenzene dissolved with the additive on the film, and then the additive is formed to adhere and aggregate on the surface of the film. Wherein the additive is an imidazo indolizine derivative, and the chemical name is 1- (4-bromophenyl) -6,7-diphenylimidazo [5,1,2-cd ] indolizine, which is PDPII for short. Preferably: The required components are mixed according to the proportion, added with DMSO/DMF mixed solvent and fully stirred until the components are completely dissolved, and the FA 0.85MA0.15Pb(I0.85Br0.15)3-xClx precursor solution is formed. And then preparing a perovskite film by spin coating, wherein the chlorobenzene anti-solvent used in the control group does not contain additives, and the experimental group contains additives with different concentrations. The resulting intermediate film is then subjected to a heat treatment. The molar concentration of the additive in the anti-solvent chlorobenzene is 0.2 to 5mmol/L. The heat treatment temperature of the film was 100 ℃. Still more preferably, it is: and adding an additive into the anti-solvent chlorobenzene, preparing a film by spin coating, heating to 100 ℃, and further assembling the battery device. In the range of 1mmol/L of the additive concentration, the stability of the battery device is gradually improved, and the concentration is changed, so that the stability of the battery device tends to be reduced. The additive is an imidazo indolizine derivative, and the chemical name is 1- (4-bromophenyl) -6,7-diphenylimidazo [5,1,2-cd ] indolizine, and PDPII for short. The organic-inorganic hybrid perovskite film has the