High-performance CsPbBr_3-xCl_x/Si heterojunction photodetectors for variable wavelength photodetection

All inorganic perovskite CsPbX₃ (X = Br, I, Cl) materials emerge as one of the popular materials in the field of optoelectronic devices due to their outstanding photoelectric properties. Their photoelectric detection performance and stability could be further improved by combining mixed halide perovskites with other semiconductor materials, achieving high-performance variable wavelength photodetectors. In this work, high-quality CsPbBr_3-xCl_x microcrystals were successfully grown on silicon (Si) substrates by chemical vapor deposition (CVD) method. By varying the Br/Cl ratio, the prepared CsPbBr_3-xCl_x heterojunction photodetectors exhibit excellent response time in the scale of microsecond and superior narrowband detection capability in a wide wavelength ranges and excellent environmental stability, achieving the maximum responsivity of 102.6 A/W and detectivity of 5.20 × 10¹² Jones under 7.8µW /cm² light illumination intensity. The results suggest an efficient and feasible strategy to the design and improvement of photodetectors for variable wavelength photodetection.