Fabrication of porous Ga₂O₃/GaN heterojunction for ultraviolet photodetector application

Abstract

Ga 2 O 3 /GaN heterojunction has important applications in optoelectronic devices. Understanding optoelectronic performance and interface relationships of the heterojunction is the key to designing optimal devices. Herein, a porous Ga 2 O 3 /GaN heterojunction is systematically investigated. Porous GaN is initially fabricated via ultraviolet-assisted electrochemical etching and porous Ga 2 O 3 is subsequently converted from porous GaN by thermal oxidation. Compared with planar Ga 2 O 3 /GaN heterojunction, porous Ga 2 O 3 /GaN heterojunction has higher crystal quality. Porous Ga 2 O 3 /GaN heterojunction exhibits a light/dark current ratio of 10520, a responsivity of 0.108 A/W, an external quantum efficiency of 52.9%, a detectivity of 1.36 × 10 12 Jones, and the response time of 0.35 s/0.13 s under 254 nm UV irradiation (0.33 mw/cm 2 ) at 0 V bias. Additionally, the operating mechanism of the device is further explored through energy band structure and carrier-transport process diagrams. This study provides valuable insights and paves the way for developing next-generation optoelectronic devices based on Ga 2 O 3 /GaN heterojunction.