High-Performance β-Ga<sub>2</sub>O<sub>3</sub> Solar-Blind Schottky Barrier Photodiode With Record Detectivity and Ultrahigh Gain via Carrier Multiplication Process
Zhe Li, Yanan Cheng, Yu Xu, Zhuangzhuang Hu, Weidong Zhu, Dazheng Chen, Qian Feng, Hong Zhou, Jincheng Zhang, Chunfu Zhang, Yue Hao
Abstract
In this letter, we demonstrate a high performance lateral β-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> solar-blind Schottky barrier photodiode (SBPD) with record detectivity (D*) and ultrahigh gain via carrier multiplication process. Due to the strong electric field, the carriers generated under the 254 nm light illumination undergo acceleration and impact ionization, contributing to the internal carrier multiplication process. Therefore, the photodetector (PD) is equipped with record D* of 2 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">16</sup> Jones and ultrahigh gain of 1.7 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sup> , combining with a high photo-to-dark-current ratio of more than 105, a responsivity of 1.2 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</sup> A/W and a large external quantum efficiency of 5.6 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</sup> %. Without the requirement of complex device structure like other avalanche PDs, our SBPD can be used as a low-cost and easy-to-integrate technology to prepare high performance solar-blind PDs.