Antisolvent-Processed One-Dimensional Ternary Rubidium Copper Bromine Microwires for Sensitive and Flexible Ultraviolet Photodetectors

Recently, newly emerging halide perovskites have aroused intensive attention in photoelectric fields in virtue of their good properties, such as well-balanced carrier transport, large light absorption coefficient, tunable band gap, and low-temperature solution processing technique. Nevertheless, their future commercial development is severely hampered by lead toxicity and instability of such materials. In this work, one-dimensional Rb2CuBr3 single-crystal microwires (MWs) were prepared by antisolvent engineering, and they were further employed as absorbers to prepare sensitive ultraviolet (UV) photodetectors. The optical band gap of Rb2CuBr3 MWs is measured to be 3.83 eV, exhibiting an excellent UV absorption. The fabricated device demonstrates a remarkable UV light detection ability with a specific detectivity of 1.23 × 1011 Jones, responsivity of 113.64 mA W-1, and response speed of 69.31/87.55 ms under light illumination of 265 nm. Meanwhile, the proposed photodetector without any encapsulation shows outstanding stability and repeatability. After storing in ambient air for 2 weeks, the light detection ability remains basically unchanged. Further, a flexible photodetector was fabricated with the same structure, which demonstrates a remarkable bending endurance. These results confirm the great potential of Rb2CuBr3 for high-performance UV photodetectors, increasing the possibility for assembly of optoelectronic systems.