Self-powered photodetectors based on transition-metal dichalcogenides: A heterojunction perspective

With the growing demand for miniaturization and low power consumption in optoelectronic devices, self-powered photodetectors (SPPDs) have attracted widespread attention due to their excellent performance without external power. Two-dimensional (2D) layered transition metal dichalcogenides (TMDs) are exemplary materials for heterojunction SPPDs, owing to their distinctive properties such as the absence of surface dangling bonds, high carrier mobility, tunable bandgap, and strong light−matter interaction. Thanks to their high-quality heterojunction interfaces, SPPDs based on TMDs exhibit broad spectral response, high detectivity, and ultrafast response speed. Moreover, various interface modulation strategies have been developed to enhance photoelectric conversion efficiency. In this review, we summarize recent advancements in heterojunction modulation strategies based on TMDs. First, the structural, optical, and electronic properties of TMDs are systematically introduced. Next, the strategies for energy band alignment engineering, interface engineering, growth modulation, and carrier modulation are reviewed according to the vertical-structure and lateral-structure photodetectors. Finally, we summarize the challenges of TMDs-based SPPDs and propose possible future research directions. This review offers a forward-looking perspective on TMDs-based SPPDs.