First Demonstration of Self-Powered Algan/Gan UV Photodetector Enabled by Non-Planar Schottky Depletion

This work for the first time demonstrates the self-powered UV photodetection on AlGaN/GaN epitaxy heterojunction platform fabricated by the Au-free CMOS-compatible processes. The innovative design of metal-GaN Schottky contact along the trench sidewall enables a good depletion field, together with the inherent polarization field at the AlGaN/GaN heterointerface to realize effective photocarrier collection at zero bias. The prototype device of 10-µm cell width achieves promising figures of merit including a low dark current of 16.4 pA, photocurrent on/off ratio of 1.1 × 10
³
, a responsivity of 0.16 A/W, and a detectivity of 8.6 × 10
¹²
Jones under 365 nm UV at 0.86 mW/cm
²
. A very low detection limit below 10
^-6
mW/cm
²
and a wide detection range with a linear dynamic range of 61 dB are also demonstrated by the proposed device, exhibiting comparable performance compared to its GaN-based self-powered counterparts.