A broadband UV-visible photodetector based on a Ga <sub>2</sub> O <sub>3</sub> /BFO heterojunction
Guoliang Ma, Weiyu Jiang, Wei‐Ming Sun, Zuyong Yan, Bingyang Sun, Shan Li, Maolin Zhang, Xia Wang, Ang Gao, Jie Dai, Zeng Liu, Peigang Li, Weihua Tang
Abstract
Abstract In this work, a well-operated broadband UV-visible photodetector based on a Ga 2 O 3 /BiFeO 3 (Ga 2 O 3 /BFO) heterojunction is fabricated and characterized. Under the ultraviolet (UV) light illumination with an intensity of 100 μ W·cm −2 at 254 nm in UVC waveband, at a biasing voltage of 2 V, an ultra-low dark current (I dark ) of 0.12 pA, a high photo-to-dark current ratio (PDCR) of 1.0 × 10 5 , a responsivity (R) of 12.0 mA·W −1 , a specific detectivity (D*) of 6.1 × 10 12 Jones, an external quantum efficiency (EQE) of 5.9%, and a UVC/visible rejection ratio ( R 235 /R 600 ) of 4.47 × 10 3 are achieved. In addition, the rise time and decay time are 0.25 s and 0.04 s, respectively. Meanwhile, the potential of the device as a self-powered photodetector is proved, and the principle of energy-band diagram is analysed for the fabricated heterojunction device. The results show that the Ga 2 O 3 /BFO heterojunction is a potential candidate for preforming desired broadband UV-visible photodetection.