Research Progress in Photoelectrochemical Photodetectors Based on Integrated Self-Supporting Photoelectrodes: Design,...

Photoelectrochemical (PEC) photodetectors (PDs) are devices that detect optical signals through photo-induced carrier migration and photoelectric conversion at the electrolyte-semiconductor interface via PEC reactions. Recently, the demand for PEC PD applications in harsh aquatic environments, such as underwater conditions, has increased. Integrated self-supporting photoelectrodes, in which photoactive materials are directly coupled with current collectors, can serve directly as working photoelectrodes. These photoelectrodes integrate functional modules-including light-absorbing, charge transport, and catalytic layers-within a unified material system, thereby reducing interfacial contact resistance, enhancing charge transfer efficiency, and establishing high stability of the photoelectrode itself. This review systematically summarizes the research progress and development trends in excellent PEC PDs based on high-performance integrated self-supporting photoelectrodes. It first introduces the working principles and performance parameters of PEC PDs and then focuses on the fabrication strategies of integrated self-supporting photoelectrodes. A comprehensive overview of the main application fields is also presented. Finally, the review identifies current challenges and future trajectories in this domain and provides a unique perspective on photoelectrode design for PEC PDs. This review sheds light on the most pioneering and potentially transformative avenues in this dynamic field. It serves as a foundation for advancing the broader application of PEC PDs.