Solar-blind ultraviolet photodetector based on vertically aligned single-crystalline β-Ga ₂ O ₃ nanowire arrays

Abstract

Abstract Vertically aligned nanowire arrays, with high surface-to-volume ratio and efficient light-trapping absorption, have attracted much attention for photoelectric devices. In this paper, vertical β-Ga 2 O 3 nanowire arrays with an average diameter/height of 110/450 nm have been fabricated by the inductively coupled plasma etching technique. Then a metal-semiconductor-metal structured solar-blind photodetector (PD) has been fabricated by depositing interdigital Ti/Au electrodes on the nanowire arrays. The fabricated β-Ga 2 O 3 nanowire PD exhibits ∼10 times higher photocurrent and responsivity than the corresponding film PD. Moreover, it also possesses a high photocurrent to dark current ratio ( I light / I dark ) of ∼10 4 and a ultraviolet/visible rejection ratio ( R 260 nm / R 400 nm ) of 3.5 × 10 3 along with millisecond-level photoresponse times.