Large-Size and Polarization-Sensitive Two-Dimensional Sn Perovskite Single Crystals

High-quality and large-size perovskite single crystals are emerging as promising materials for optoelectronic devices including solar cells, high energy radiation sensing, and visible light detection. Low-dimensional perovskite structures have aroused great attention recently for its unique properties such as large carrier mobility and anisotropic properties. However, there are lack of methods to grow high-quality and large-size low-dimensional perovskite single crystals. Herein, by using ethylene glycol as solvent to increase the coordination between precursor and solutes, the nucleation barrier is increased allowing slow nucleation and crystal growth. As a result, large-size two-dimensional (2D) tin perovskite single crystals with smooth surface are synthesized for the first time. A photodetector is fabricated based on this single crystal and it shows linear-polarized light sensing. The theoretical simulation is explored to explain the anisotropic properties of 2D perovskite structures. In the end, a heterojunction is fabricated based on the epitaxy growth of 2D lead perovskite on the 2D tin perovskite single crystal.