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

In this letter we present a high performance <tex-math notation="LaTeX">ε </tex-math> -Ga 2 O 3 solar-blind photodetector (SBPD) with asymmetric Schottky electrodes. The <tex-math notation="LaTeX">ε </tex-math> -Ga 2 O 3 films were heteroepitaxially grown on <tex-math notation="LaTeX">c </tex-math> -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 ~ 10 2 with low dark current of 25 pA at <tex-math notation="LaTeX">V = 6 </tex-math> V. A high photo-to-dark-current ratio of <tex-math notation="LaTeX">5.7× 10^4 </tex-math> under 254 nm light illumination was measured. Furthermore, the SBPD exhibits an ultrahigh detectivity and external quantum efficiency of <tex-math notation="LaTeX">4.2× 10^14 </tex-math> Jones and <tex-math notation="LaTeX">4.1 \,\,× \,\,10^4 </tex-math> %, 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 <tex-math notation="LaTeX">ε </tex-math> -Ga 2 O 3 in the future photodetector applications.