Single β-Ga2O3 microbelt solar-blind photodetector with high specific detectivity, high rejection ratio and fast speed

Abstract

An ideal solar-blind photodetector should possess high responsivity, low dark current, high speed, high spectral selectivity, high stability and a facile fabrication method. In this work, a high-quality single β-Ga2O3 microbelt photodetector is fabricated through low-pressure chemical vapor deposition and in situ atmospheric pressure annealing techniques. Due to the high quality and low defect density, this device shows a peak responsivity of 9.47 A W−1 at 256 nm, a dark current of 1 pA and an ultrashort fall time of 1.37 μs under 20 V bias. Moreover, an ultrahigh specific detectivity of ∼1014 Jones and an extremely large solar-blind/ultraviolet A rejection ratio of nearly 105 have also been achieved, suggesting the excellent sensitivity and wavelength selectivity of our single β-Ga2O3 microbelt photodetector. Besides that, the β-Ga2O3 microbelt photodetector exhibits excellent mechanical and long-term stabilities. Our findings provide a facile and promising route to develop high performance solar-blind UV photodetectors.