Boosted ultraviolet photodetection of AlGaN quantum-disk nanowires via rational surface passivation

Abstract Self-assembled AlGaN nanowires (NWs) are regarded as promising structures in the pursuit of ultraviolet photodetectors (UV PDs). However, NW-based PDs currently suffer from degraded performance partially due to existence outstanding surface-related defects/traps a result their large surface-to-volume-ratio. Here, we propose an effective passivation approach suppress such surface states via tetramethyl ammonium hydroxide (TMAH) solution treatment. We successfully demonstrate fabrication UV using TMAH-passivated quantum-disk NWs and investigate optical electrical properties. In particular, dark current can be significantly reduced by order magnitude after passivation, thus leading improvement photoresponsivity detectivity. The underlying mechanism for boost ascribed elimination oxygen-related on NW surface. Consequently, PD with low 6.22 × 10 −9 A, responsivity 0.95 A W −1 , high detectivity 6.4 11 Jones has been achieved.