GaN-Based HEMT-Type VUV Phototransistors With Superior Triple-Mode Photodetection

In this work, a superior vacuum UV phototransistor (VUV PT) in the form of GaN-based HEMT architecture is demonstrated. With tunable gate/drain bias (
${V}_{\text {GS}}/{V}_{\text {DS}}{)}$
, the HEMT-type VUV PT is switchable among three detection modes including photoconduction (–5/10 V), photovoltaics (±0.05/0 V), and self-powering (0/0 V). Strikingly, the device demonstrates record-high responsivity and detectivity under all the operation modes thanks to structural advantages in AlGaN/GaN heterojunction, including the shallow active region, unique band inclinations, and stable surface conditions. Our work highlights the great abilities of GaN-based HEMT as a promising platform to build multi-functional photoelectric systems.