PbI₂ Nanosheets for Photodetectors via the Facile Cooling Thermal Supersaturation Solution Method

As a potential candidate for modern optoelectronics, two-dimensional PbI2 nanosheets have received much attention. In this paper, we report a simple, low-cost cooling supersaturated aqueous solution method for the controllable morphology growth of high-quality PbI2 single crystals. The fluorescence kinetics of PbI2 nanosheets was investigated by the temporally and spatially resolved spectrum measurements. The body center region of as-prepared PbI2 nanosheets showed a higher density of defect states than that at the edges or corners. In addition, the as-prepared PbI2 nanosheet-based photodetectors exhibit stable and efficient performance, including the large on/off ratio (1.371 × 103), high light response (40 mA/W), and high detection sensitivity (3.31 × 1010 J)