Synthesis And Property Study Of Antimony/Bismuth-Based Hybrid Perovskite Semiconductors

Within the last years,the synthesis and property study of lead organometal halide perovskites?Pb-OHPs?represented by APbX3?A=organic cation;X=halogen?has turned into one of the hot topics in synthesis chemistry and material science.Although such materials have outstanding performance,their poor stability and toxicity of lead have always been a shortcoming that hinders its practical application.In this thesis,we selected the low or non-toxic antimony and bismuth halides as inorganic components,and the hydrophobic phenylpyridine derivatives as organic components.By designing the in-situ organic reactions to regulate the hydrophobicity of the organic components,a series of hybrid perovskite semiconductors with different water stability were synthesized.Theoretical calculations were also employed to obtain the regulation and synthesis strategies for stable hybrid materials.The photoconductive performances of the hybrid materials were fully studied.The specific research contents are as follows:1.The hydrogen-bond-free?HBF?cations were used to synthesize two one-dimensional hybrid perovskites,namely?1-methyl-4-phenylpyridin-1-ium?BiI4?denoted as Me4ppi-BiI4?and?1-ethyl-4-phenylpyridin-1-ium?SbI₄?denoted as Et4ppi-SbI₄?.The water stabilities studies indicate that they can endure 75%relative humidity for at least 35 days for Me4ppi-BiI4 and 3 days for Et4ppi-SbI4;both being obviously more stable than the corresponding?CH₃NH₃?₃M₂X₉–type material.Importantly,they show good photoconduction behaviors with short rise and decay recovery time,and exhibit excellent repeatabilities of photocurrent.This work not only provided two important moisture stable Pb-free hybrid perovskites for photoconductivities applications,but also demonstrate an effective strategy to get stable Pb-free hybrid perovskite.2.Based on the above synthesis strategy,two stable zero-dimensional Sb-based hybrid perovskites were synthesized,namely?1-methyl-4-phenylpyridin-1-ium?4Sb4I16(denoted as Me4ppi-Sb₄I₁₆)and?1-butyl-4-phenylpyridin-1-ium?₄Sb₄I₁₆(denoted as Buty4ppi-Sb₄I₁₆).They can endure 75%relative humidity for at least 50 days,with photocurrent on/off ratios of40.54 and 14.39 respectively,both higher than those of Me4ppi-BiI4 and Et4ppi-Sb I4.All these indicate that the two zero-dimensional Sb-based hybrid semiconductors can be used as potential photodetection materials.3.Based on the“soft interaction”strategy,we synthesized a Pb-free hybrid perovskite-like semiconductor:?H-3-phenylpyridin-1-ium?SbI₄?denoted as H3ppi-Sb I₄?,where the antimony tetraiodide anionic chains and the positive charged 3ppi ions assembled via only coulomb interactions.It is the first report of Sb-based hybrid perovskite perovskite semiconductor assembled by coulomb interaction only.H3ppi-Sb I4 exhibits good light absorption and excellent repeatability of photocurrent,and is expected to be a new Pb-free photoconductivity material.