Ferroelectric CsGeI<sub>3</sub> Single Crystals with a Perovskite Structure Grown from Aqueous Solution
Rui Chen, Chang Liu, Yangyang Chen, Chao Ye, Shi Chen, Jinrong Cheng, Shixun Cao, Shenghao Wang, Anyang Cui, Zhigao Hu, He Lin, Jinlong Wu, Xiangyang Kong, Wei Ren
Abstract
All-inorganic perovskite halide semiconductors have been noticed for applications in photovoltaics, light-emitting diodes, lasers, and photodetectors, thanks to their exceptional optoelectronic characteristics. As a typical example, CsGeI3 was previously investigated in the forms of quantum dots and thin films. Here, we developed a technique based on aqueous solution to synthesize millimeter-level-sized CsGeI3 single crystals. The ferroelectric and photoelectric functionalities of the as-grown crystals were examined and compared with the prediction from density functional theory calculation. These findings not only provide a new route to make germanium-based perovskite single crystals but also introduce possible prospects for ferroelectric photovoltaics.