Self‐Powered AlGaN/GaN Photovoltaic‐Integrated UV Photodetector: Rapid Response with Persistent Photoconductivity Suppression

Abstract Conventional GaN‐based UV photodetectors (PDs) suffer from prolonged turn‐off dynamics and high residual off‐state currents, severely limiting their use in high‐speed optoelectronic applications. In this work, a self‐powered, on‐chip AlGaN/GaN photovoltaic‐photodetector integrated configuration (PPIC) that combines photovoltaic energy harvesting and UV photodetection is proposed to address these challenges. Taking advantage of the high conductivity and carrier mobility of the 2D electron gas (2DEG) at AlGaN/GaN heterojunction, the PPIC facilitates an internal gain under the field associated with the photovoltaic (PV) bias and achieves enhanced static photo‐responsivity. Crucially, the PV dynamically biases the PD in synchronization with the UV illumination, ceasing the residual photocarrier collection in dark conditions by eliminating the collection field, thereby effectively suppressing residual current and enhancing frequency response. Apart from competitive static self‐powered performance under 365 nm UV, the PPIC with 0.16 mm2 PV area exhibits outstanding transient performance, including the 3‐dB bandwidth of 6230 Hz and ultrafast rise and fall times of 61.18 and 97.79 µs respectively – over 100‐fold improvement compared to the conventional PD with external bias. Fabricated with CMOS‐compatible processes, the PPIC offers a solution for high‐speed, self‐powered UV photodetection, with transformative potential in applications like optoelectronic communication and UV imaging.