Ga2O3@Al2O3 Core–Shell Nanowires for High-Performance Solar-Blind Photodetectors

High-performance solar-blind photodetectors (SBPDs) have been indispensable in both military and civilian applications. Herein, Ga 2 O 3 @Al 2 O 3 core–shell nanowires (NWs) are synthesized by plasma-enhanced atomic layer deposition (PEALD) Al 2 O 3 layer on the surface of Ga 2 O 3 nanowires. The Ga 2 O 3 @Al 2 O 3 NW has a length of tens of micrometers, and the thickness of Ga 2 O 3 and Al 2 O 3 layers in the NW is approximately 30 and 5 nm, respectively. The PEALD method passivates surface defects to improve the crystal quality of Ga 2 O 3 . The metal–semiconductor–metal (MSM) Ga 2 O 3 @Al 2 O 3 NW-based SBPDs exhibit a superhigh sensitivity of 1.07 × 10 3 A/W and a high response speed of less than 83 ms at 5 V bias voltage under 254 nm irradiation. Additionally, the Ga 2 O 3 @Al 2 O 3 NW PDs exhibit a superhigh specific detectivity of 3.38 × 10 11 Jones, an external quantum efficiency (EQE) of 5.22 × 10 5 %, and a high deep ultraviolet (DUV)/visible responsivity rejection ratio ( R 254/405 ) of 4.81 × 10 2 . These results suggest that this method is an effective way to design and prepare high-performance photonic devices.