Growth and Photoelectric Properties Characterization of Large-Sized CH3NH3PbBr3 Crystal.

As a new type of semiconductor material, halide perovskite materials has the advantages of low cost and excellent photoelectric conversion performance. Various photoelectric devices based on the halide perovskite materials have begun to be gradually applied. Polycrystalline thin films are still the main research direction, however, they have the disadvantages of disordered morphology and many impurities. In contrast, single crystals have the characteristics of no grain boundaries and low defects. Therefore, the research based on large-size single crystals gained widely concerned. In this paper, a set of internal and external reverse temperature control cycle filtration growth devices was designed. The CH₃NH₃PbBr₃ single crystal with a diameter of more than 60 mm was prepared by the combination of inverse temperature crystallization and seed crystal. The phase, microstructure, and optical and electrical properties of the crystal samples were studied. The crystal belongs to the cubic system with space group of Pm3m. The ultraviolet-visible absorption spectrum shows that the absorption cut-off edge is about 576 nm and the fluorescence emission spectrum peak is 552 nm. The rocking curve shows that the half width at maximum of the crystal (100) plane is 91. 42". The wafer after cutting and polishing is sensitive to photo response, and the on-off ratio is 2. 4 x 10⁴. [ABSTRACT FROM AUTHOR]