Fabrications of Halide Perovskite Single-Crystal Slices and Their Applications in Solar Cells, Photodetectors, and LEDs

Halide perovskites constitute a class of novel materials with remarkable photoelectronic properties and have been widely investigated for various photoelectronic devices, including solar cells, photodetectors, light emitting diodes, etc. In comparison with perovskite polycrystalline films, perovskite single crystals possess the features of being free of grain boundaries and having low trap densities and have exhibited better photoelectronic properties and ambient stability. The proper applicable thickness ranges of perovskite crystals are different for various photoelectronic devices: for example, the appropriate thickness ranges for solar cells and X-/γ-ray detection are hundreds of nanometers and several millimeters, respectively. Therefore, it is essential to develop feasible methods to prepare perovskite single-crystal slices with the appropriate thickness. Although several methods have been adopted to prepare perovskite single-crystal slices (PSCSs), thick PSCSs restrict the performance of the corresponding devices. In this review, we speculate that the main difficulty lies in the preparation of thinner PSCSs. Therefore, their excellent performance for applications in photoelectronic devices needs to be proved by developing suitable methods to prepare thinner PSCSs. Nevertheless, there have still been few reports about PSCSs and few groups participating in the development of PSCSs. Therefore, this paper reviews the research progress of PSCSs in preparations and applications, which may provide valuable information for the further development of PSCSs and call on more researchers to participate in the research.