Large-scale synthesis of CH3NH3BF4 crystal and its application on CH3NH3PbBrx(BF4)(3-x) perovskite thin films

• Published in: Chemical physics letters 2020-09, Vol.754, p.137638, Article 137638
• Main Authors: Yang, Lijun, Wu, Dongxue, Tang, Jun, Hao, Yawei, Wang, Jingchuan, Zhao, Xiaochong, Yang, Pan
• Format: Article
• Language: English
• Subjects: CH3NH3BF4; CH3NH3PbBrx(BF4)(3-x); Crystal; Perovskite; Synthesis; Thin films
• ISSN: 0009-2614; 1873-4448
• DOI: 10.1016/j.cplett.2020.137638

[Display omitted] •CH3NH3BF4 synthesized with CH3NH2 and HBF4, showed high purity and effective rate.•BF4− results a bigger particle diameter and a wider UV-vis absorbance band.•BF4− results a red-shift PL emission peak and a longer fluorescence lifetime•BF4− increases the charge carrier lifetime and decrease the rate of recombination. A simple and environment friendly method for the synthesization of CH3NH3BF4, which exhibits high purity and yield. With close ionic radius, BF4− was doped into CH3NH3PbBr3 perovskite as substitution of Br− to improve the chemical stability of lead halide perovskite. The results show that the doped-BF4− can increase the charge carrier lifetime of CH3NH3PbBrx(BF4)(3-x) perovskite thin films, meanwhile decrease the rate of recombination. This is mainly due to the larger ionic radius of BF4−, which brings about a lower degree X-ray diffraction angle shift, wider ultraviolet visible spectrophotometer absorbance band, red-shift photoluminescence emission peak, and longer fluorescence lifetime.