High-Performance Metal-Organic Chemical Vapor Deposition Grown ε-Ga2O3 Solar-Blind Photodeterctor With Asymmetric Schottky Electrodes

In this letter we present a high performance epsilon-Ga2O3 solar-blind photodetector (SBPD) with asymmetric Schottky electrodes. The epsilon-Ga2O3 films were heteroepitaxially grown on c-plane sapphire by metal-organic chemical vapor deposition (MOCVD). The SBPDs were fabricated in the form of lateral interdigitated Schottky electrodes composed of a Pt/Ti/Au metal stack and a Ti/Au metal stack. The SBPD shows a rectification ratio of similar to 10(2) with low dark current of 25 pA at V = 6 V. A high photo-to-dark-current ratio of 5.7 x 10(4) under 254 nm light illumination was measured. Furthermore, the SBPD exhibits an ultrahigh detectivity and external quantum efficiency of 4.2 x 10(14) Jones and 4.1 x 10(4) %, respectively. Most importantly, the SBPD possesses an ultrahigh responsivity of 84 A/W with a fast response speed of 100 ms, suggesting the promise of epsilon-Ga2O3 in the future photodetector applications.