Cs2Pb4Br10: A layered perovskite shows large birefringence

Birefringent crystal is an important photoelectric functional material widely used in laser polarizationtechnology, optical polarization modulation and detection. The research on the reported Pb-Br-Cs system shows that there is no relevant research on the source of birefringence. Therefore, we have carried out the birefringence study of Pb-Br-Cs series crystals, and found that the birefringence of some Pb-Br-Cs substances are lower than 0.05, but only the layered perovskite Cs2Pb4Br10 has a large birefringence (0.392 @ 550 nm). Therefore, layered perovskite metal halides are expected to be candidates for birefringent crystals.

Automated summary

Birefringent crystal is a significant photoelectric functional material used extensively in laser and optical fields. The study on Pb-Br-Cs series crystals reveals that only the layered perovskite Cs2Pb4Br10 exhibits a large birefringence.