Over 5 × 10³-Fold Enhancement of Responsivity in Ga₂O₃-Based Solar Blind Photodetector via Acousto-Photoelectric Coupling.

Abstract

The emergence of the wide-band-gap semiconductor Ga₂O₃ has propelled it to the forefront of solar blind detection activity owing to its key features. Although various architectures and designs of Ga₂O₃-based solar blind photodetectors have been proposed, their performance still falls short of commercial standards. In this study, we demonstrate a method to enhance the performance of a simple metal-semiconductor-metal-structured Ga₂O₃-based solar blind photodetector by exciting acoustic surface waves. Specifically, we demonstrate that under a bias voltage of 100 mV and a radio frequency signal of 20 dBm, the responsivity and detectivity can increase from 2.78 to 1.65 × 10⁴ A/W and from 8.35 × 10¹⁴ to 2.66 × 10¹⁶ jones, respectively, rivaling a commercial photomultiplier tube. The over 5 × 10³-fold enhancement in responsivity could be attributed to the acousto-photoelectric coupling mechanism. Furthermore, since surface acoustic waves can also serve as signal receivers, such photodetectors offer the prospect of dual-mode detection. Our findings reveal a promising pathway for achieving high-performance Ga₂O₃-based electronics and optoelectronics.