Low temperature-processed stable and high-efficiency carbon-based CsPbI2Br perovskite solar cells by additive strategy

All-inorganic perovskite solar cells require high-temperature preparation processes, which severely hinders their further commercial development. Inorganic perovskite materials have a high crystallization barrier, so the crystallinity is poor under low temperature conditions, resulting in poor device performance. Therefore, it is an important challenge to develop an excellent low-temperature preparation process. In this paper, the crystallization kinetics of the CsPbI 2 Br perovskite film under low temperature conditions was studied, and it was found that the perovskite was not completely crystallized during low temperature crystallization , and PbI 2 remained. The PbI 2 residue not only caused the appearance of lead defects but also formed insoluble CsBr due to the insufficient reaction of the raw materials. Through the interaction between the organic molecules 3-Amino-3-(3-pyridyl)propionic Acid (PA) and PbI 2 , the crystallization reaction process can be effectively improved. Eliminating the residual PbI 2 also effectively inhibited the precipitation of CsBr, thereby significantly improved the crystallinity of CsPbI 2 Br. Efficiencies of 10.95% are achieved for low-temperature-processed CsPbI 2 Br planar-architecture FTO/SnO 2 /CsPbI 2 Br/carbon, and the obtained device also showed good stability in the air.