High-Detectivity <i>β</i>-Ga₂O₃ Microflake Solar-Blind Phototransistor for Weak Light Detection
Shunjie Yu, Xiaolong Zhao, Mengfan Ding, Pengju Tan, Xiaohu Hou, Zhongfang Zhang, Wenxiang Mu, Zhitai Jia, Xutang Tao, Guangwei Xu, Shibing Long
Abstract
This letter reports a high-performance solar-blind phototransistor based on N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> -annealed 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> microflake for weak light detection. The phototransistor exhibits an ultra-low dark current of 27 fA, a high external quantum efficiency of 8.36 x 107%, a photo-to-dark-current ratio of 1.08 x 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">7</sup> , a low power consumption of 2.92 pW, and a narrow-band response with a cut off wavelength of 263 nm. In addition, the spectral selectivity can be well modulated by the gate bias and reaches a maximum R <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">240</sub> /R <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">400</sub> ratio of 2.4 x 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sup> . Especially, an ultra-high responsivity (R) of 1.71 x 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 record-high detectivity (D*) of 1.19 x 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">18</sup> Jones have been achieved under 254nm illumination of 4.1 μW/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . The superior weak-light-detection performance of the device makes it one of the best 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> detectors towards solar-blind photodetection application.