Self-Powered Photodetectors Based on PdSe ₂ / Al ₂ O ₃ /AlGaN Schottky Heterojunctions for Solar-Blind Ultraviolet Communication

Generally, the slow response occurs in the AlGaN-based self-powered solar-blind photodetectors (SBPDs), owing to the low carrier mobility and high density of surface traps in AlGaN. To tackle the issues, PdSe2/Al2O3/AlGaN SBPDs have been proposed. Thanks to the direct growth of single-crystal PdSe2 with high work function and excellent mobility for constructing high-quality Schottky heterojunctions with a sharp interface and thin high-k Al2O3 interlayer for passivating dangling bonds at the interface and enhancing the Schottky barrier height, the as-prepared self-powered SBPDs demonstrate a fast response speed of 2.9/3.5 ms, a high responsivity of 95.3 mA/W, and an exceedingly good detectivity of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${1}.{41}\times {10} ^{{12}}$ </tex-math></inline-formula> Jones @ 0 V under 254 nm light irradiation. Moreover, a solar-blind light communication (SBLC) system based on the device has been proposed. This work provides an effective approach for fabricating self-powered SBPDs towards application in the SBLC system.