Charge Transfer in Photoexcited Cesium–Lead Halide Perovskite Nanocrystals: Review of Materials and Applications

Cesium–lead halide (CsPbX3) perovskite nanocrystals (PNCs) have attracted significant attention from researchers because of their essential optoelectronic properties, especially long charge-carrier transfer, high efficiency in visible-light absorption, long excited-state lifetimes, etc. Because of these properties, these materials exhibit outstanding charge transfer and charge separation, which allows them to be used for solar cell applications. Recently, CsPbX3 perovskites have emerged as photocatalysts. In photovoltaics or photocatalysis, upon photoexcitation, the exciton dissociates, and the electron/hole is transmitted from the conduction/valence bands to the electron/hole acceptors. Therefore, it is essential to understand how charge transfer occurs at the PNC interface, which can help a researcher maximize the output in solar cells and photocatalytic efficiency. Specifically, we emphasize using PNCs as electron and hole donors in this review. We have outlined different charge-transfer dynamics based on critical factors and discussed their optoelectronic properties. Electron/hole-transfer dynamics are the most concerning characteristic; thus, we reviewed the relevant literature that reported efficient electron/hole-transfer performance. In the end, we highlighted recent developments in the use of PNCs as photocatalysts in organic synthesis.