Disperse PbI2 clusters with 4-Difluoromethyl-Benzylamine Hydrochloride to improve the efficiency and stability of perovskite solar cells

• Published in: Optical materials Vol. 145; p. 114426
• Main Authors: Hou, Mengjun, Liu, Xingchong, Fu, Yu, Wang, Hanyu, Zhao, Weikang, Li, Haimin, Ni, Yafei, Lei, Yue, Zou, Wenjing, Peng, Yongshan, Luo, Hu, Feng, Qirui, Ye, Peihan, Liu, Shuqian, Tang, Yanling
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.11.2023
• Subjects: 4-Difluoromethyl-Benzylamine Hydrochloride; Defects passivation; Modified layer; Organic ammonium salt; Perovskite solar cells; 4-Difluoromethyl-Benzylamine Hydrochloride; Defects passivation; Organic ammonium salt; Modified layer; Perovskite solar cells
• ISSN: 0925-3467; 1873-1252
• DOI: 10.1016/j.optmat.2023.114426

Generally, an excess of PbI2 is used in the perovskite precursor solution to increase the crystallinity of the perovskite. However, excessive PbI2 will form PbI2 clusters during the annealing process of the perovskite film, which will cause the decomposition of perovskite solar cells (PSCs) and affect the stability of the device. Here we use 4-Difluoromethyl-Benzylamine Hydrochloride (4F2M-BACl) to do interfacial doping of the perovskite film to passivate the defects on the surface of the perovskite film and disperse the PbI2 clusters through the interaction with PbI2. Under the passivation effect of 4F2M-BACl, the power conversion efficiency (PCE) of PSCs was increased from 18.51% to 21.51%, and the hysteresis indicator (HI) was lower. In addition, the hydrophobic functional group F and benzene ring of 4F2M-BACl and the dispersing effect of 4F2M-BACl on PbI2 have significantly improved the stability of the device. Unencapsulated devices with 4F2M-BACl modification were able to maintain over 85% of the initial PCE after 170 h at 80% relative humidity (RH). •Using 4-difluoromethyl-benzylamine hydrochloride to disperse PbI2 clusters on the surface of thin films.•4-difluoromethyl-benzylamine hydrochloride for surface passivation to reduce surface defects.•Large organic cations provide stability.