Solution Spin-Coated BiFeO<sub>3</sub> Onto Ga<sub>2</sub>O<sub>3</sub> Towards Self-Powered Deep UV Photo Detector of Ga<sub>2</sub>O<sub>3</sub>/BiFeO<sub>3</sub> Heterojunction
Guoliang Ma, Ang Gao, Zeng Liu, Wei‐Ming Sun, Shan Li, Zuyong Yan, Weiyu Jiang, Bingyang Sun, Xiaohui Qi, Peigang Li, Weihua Tang
Abstract
Ga <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> is one of the most suitable semiconductor materials for performing deep UV photoelectric detection. In this work, a self-powered deep UV photodetector based on a Ga <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> /BFO heterojunction is fabricated via solution spin-coating and metal-organic chemical vapor deposition (MOCVD) methods. Without biasing driven, the device achieves an extreme low dark current ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${I}_{dark}$ </tex-math></inline-formula> ) of 8.38 fA, a photo-to-dark current ratio ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">PDCR</i> ) of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1.66\times10$ </tex-math></inline-formula> <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</sup> , a high specific detectivity ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${D} \ast $ </tex-math></inline-formula> ) of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$6.1\times 10^{12}$ </tex-math></inline-formula> Jones and an open-circuit voltage ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${V}_{\textit {oc}}$ </tex-math></inline-formula> ) of 0.55 V responding to deep UV irradiation (254 nm in this work). Through analyzing the band diagram of the heterojunction, the intrinsic physical characteristics of the photodetector are discussed. Results show that the photodetector has excellent deep UV signal detecting ability, indicating that Ga <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> /BFO heterojunction is a potential candidate for performing self-powered deep UV photodetection.