Proceedings of Online Meetup - Beyond Lead Halide Perovskites: Syntheses and Applications of Metal Halide Semiconductors (MABP)
Publication date: 23rd April 2020
Complex metal halides are intensively explored primarily in the context of their potential applications as absorber materials for perovskite photovoltaics. Despite a significant progress achieved with perovskite solar cells based on complex lead halides, it is still unclear if they can be practically useful because of the unresolved so far severe operational stability issues. At the same time, the success and challenges faced with lead-based perovskites stimulate active screening of other complex metal halides in order to develop more stable and, probably, even more efficient absorber materials.
In this work we explored for the first time a family of Te(IV) polyhalides A2TeX6I2, where A represents organic cation and X denotes Br or I. The crystal structures of these compounds feature [TeX6] octahedra interconnected by I2 bridge molecules. These compounds can be synthesized using a simple single-step procedure, which makes them available on a large scale. The tellurium complex bromides and, particularly, iodides exhibited interesting optical properties favoring their photovoltaic applications (e.g. band gaps below 1.5 eV). Thin films of the tellurium halides showed semiconductor behavior and revealed strong photoconductivity effects enabling their application as active materials in efficient photodetectors.