Improving the Operational Stability of the Sb2Se3-Based Self-Powered Photodetector via Interfacial Engineering

Originating from photovoltaic devices, self-powered photodetectors (SPPDs) have low power consumption and show promising applications in photoelectric imaging and optical communications. Many efforts have been devoted to improving their photodetection performances, including responsivity, detectivity, and response time. However, work on their operational stability, one of the key parameters of applied PDs, is still rare. Here, using an interfacial engineering method, we improve the operational stability of the representative Sb2Se3-based SPPD. The Sb2O3 modification layer is applied at the interface between the Sb2Se3 and TiO2 layers and characterized systematically. With the optimized fabrication of the Sb2O3 layer, the operational stability under both air ambient and underwater conditions is significantly enhanced. Moreover, the performances of the SPPD, including responsivity, detectivity, and response time, are improved to 0.45 A/W, 2.70 × 1013 Jones, and 81.5/75.0 ns, respectively. Specifically, without encapsulation, the photoresponse and key photodetection parameters of the devices vary by only around ten percent after working underwater. Our work provides a facile and effective way to modify the interfacial properties of the Sb2Se3 heterostructure and improve the operational stability of the SPPD.