Method for preparing perovskite solar cell by steam assistance

Abstract

The invention belongs to the field of solar cells, and particularly relates to a method for preparing a perovskite solar cell by steam assistance. The method comprises the steps of evaporating an electron transmission layer on a substrate; evaporating a PbI2 layer on the electron transmission layer; dissolving FAI and I2 in isopropyl alcohol, placing the isopropyl alcohol opposite to the PbI2 layer after another one piece of glass is coated, heating in a vacuum environment so that FAI and iodine molecules are sublimed to a surface of the PbI2 plating layer and react to form a perovskite crystal, and obtaining a perovskite light absorption layer after annealing; and sequentially spin-coating a hole transmission layer and evaporating a metal counter electrode to prepare the perovskite solarcell. A continuous, uniform, compact and high-quality perovskite thin film can be obtained by slow phase reaction between a vapor phase and a solid phase and by a steam assistance method; and meanwhile, excessive amount of iodine is added and doped in the perovskite light absorption layer, thus, the proportion of Alpha-FAPbI3 with photosensitivity in perovskite is increased, the crystal defect concentration is reduced, and the photoelectric conversion efficiency of the cell is improved.

Description

technical field [0001] The invention belongs to the field of solar cells, in particular to a method for steam-assisted preparation of perovskite solar cells. Background technique [0002] Energy is an important basic condition for social and economic development. So far, the development of human society has mainly relied on fossil energy. Non-renewable energy represented by fossil energy such as oil, coal, and natural gas has limited reserves, high development costs, and is likely to cause environmental pollution during use. It is increasingly unable to meet the ever-expanding energy demand and environmental protection requirements. Alternative clean energy sources have attracted attention, and solar cell power generation is considered to be one of the most promising methods. Solar cells can use solar energy to directly convert into electrical energy, which can provide inexhaustible clean energy for the development of human society. It is an important countermeasure for hum...

AI Technical Summary

Problems solved by technology

How to prepare high-quality perovskite light-absorbing layer films largely determines the photoelectric conversion efficiency of solar cell devices. The traditional method of preparing perovskite films is mainly the solution method, which can give full play to the preparation of small-area cells. It has advantages, but it also has great limitations. With the increase of the battery area to be prepared, the problems caused by the spin coating method will be more serious. Since the solution method is a liquid phase reaction to quickly generate perovskite, Difficult to control the growth of perovskite crystals, resulting in rough and porous films

In addition, most of the existing materials for preparing perovskite light-absorbing layers use MAI, but MAPbI 3 The thermal stability of the product is not good enough to pass the "double 85 test", while FAPbI 3 Good thermal stability, but when using pure FAI to prepare the perovskite light-absorbing layer, it is easy to produce β-FAPbI without photosensitivity 3 (yellow phase), resulting in a serious drop in battery efficiency, and the prior art cannot prepare large-size FAPbI 3 The perovskite light-absorbing layer severely restricts the commercialization of perovskite solar cells

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