Hydration of mixed halide perovskites investigated by Fourier transform infrared spectroscopy
Zhixing Gan,
Zhizhou Yu,
Ming Meng,
Wei Xia,
Xiaowei Zhang
Affiliations
Zhixing Gan
Jiangsu Key Lab on Opto-Electronic Technology, Center for Quantum Transport and Thermal Energy Science, School of Physics and Technology, Nanjing Normal University, Nanjing 210023, China
Zhizhou Yu
Jiangsu Key Lab on Opto-Electronic Technology, Center for Quantum Transport and Thermal Energy Science, School of Physics and Technology, Nanjing Normal University, Nanjing 210023, China
Ming Meng
School of Physics and Telecommunication Engineering, Zhoukou Normal University, Zhoukou 466001, China
Wei Xia
Jiangsu Key Lab on Opto-Electronic Technology, Center for Quantum Transport and Thermal Energy Science, School of Physics and Technology, Nanjing Normal University, Nanjing 210023, China
Xiaowei Zhang
Department of Electrical Engineering and Computer Science, Ningbo University, Ningbo 315211, China
The mixed lead halide perovskites are promising candidates for solar cells, but the intrinsic instabilities due to phase segregation, halide migration, and hydration hinder the practical applications. Currently, less attention is paid to the humidity induced degradation. This important issue of mixed halide perovskites is now investigated by Fourier transform infrared (FTIR) spectroscopy. After hydration of CH3NH3Pb(I1−xBrx)3, a broad band at around 3200 cm−1 of –OH vibration appears in the FTIR spectra and the bands in the range of 1200–1700 cm−1 become much stronger. The dominant FTIR mode at 1660 cm−1 due to the intermediate complex is sensitive on hydration, implying it could be used as a characteristic peak to evaluate the hydration degree of mixed halide perovskites. These information are of interest to optimize the crystal structure of this material to improve the stability so that to promote the photovoltaic applications.
