High-performance fully transparent Ga2O3 solar-blind UV photodetector with the embedded indium–tin–oxide electrodes

Transparent ultraviolet (UV) photodetectors have attracted the increasing attention due to their giant potential in integrated transparent electronics applications. In this work, a fully transparent metal-semiconductor-metal (MSM) solar-blind UV photodetector with embedded indium–tin–oxide (ITO) electrodes based on Ga2O3 films was successfully designed and constructed for the first time. A novel method to prepare a MSM photodetector with embedded electrode structure is proposed by selective epitaxying β-Ga2O3 thin films on c-plane sapphire substrate with ITO inter-digital electrodes prepared in advance. An ultra-low dark current of 1.6 pA, a superb UV-to-visible rejection ratio of 1.3 × 106 (R250/R400), a high specific detectivity of 7.4 × 1015 Jones and a large responsivity of 74.9 A/W can be observed in our device at 10 V, which are superior to those of other reported transparent UV photodetectors based on Ga2O3 films. The strong and uniform electrical field in β-Ga2O3 between two adjacent embedded ITO electrodes, and the high quality of β-Ga2O3 films should be responsible the excellent solar-blind photodetection performance. Our findings pave a new way to realize a high-performance fully transparent Ga2O3 solar-blind UV photodetector, which has the giant potential for applications in future transparent electronics.