Self-powered CsPbBr3 photodetector with ultra-low dark current and high-temperature robustness enabled by asymmetric Au/Ti Schottky contacts

Self-powered perovskite photodetectors (PDs) have emerged as an attractive platform for energy-efficient and low-power optoelectronic applications. However, achieving superior self-powered photodetection performance with wide linear dynamic range (LDR) and high-temperature stability remains challenging, due to the formidable defect-assisted ion migration and thermally activated carrier injection. Here, we demonstrate a thermally robust self-powered PD incorporated with a high-quality chemical vapor deposition grown CsPbBr 3 nanoplate and engineered Schottky contacts. The asymmetric Ti and Au contacts establish an effective built-in electric field that enables self-powered operation, and the adequate Schottky barrier efficiently suppresses thermally activated dark current. Meanwhile, the high crystalline quality of CsPbBr 3 nanoplates, characterized by a low defect density, minimizes trap-assisted carrier transport or ion migration, which contributes to the reduction of dark current and enhancement of photodetection robustness at elevated temperatures. As a result, the device exhibits impressive self-powered photodetection figures of merit with an ultralow dark current (∼-0.25 pA), a wide LDR of 137 dB, and a reliable operation up to 450 K. Notably, the responsivity is further enhanced at elevated temperatures. This work provides a clear physical strategy for realizing outstanding self-powered perovskite PDs with high-temperature robustness.