Self-powered MXene/GaN van der Waals Schottky ultraviolet photodetectors with exceptional responsivity and stability
Yu Ding, Xiangming Xu, Zhe Zhuang, Yimeng Sang, Mei Cui, Wenxin Li, Yan Yu, Tao Tao, Weizong Xu, Fangfang Ren, Jiandong Ye, Dunjun Chen, Hai Lu, Rong Zhang, Husam N. Alshareef, Bin Liu
Abstract
High-responsivity and energy-saving ultraviolet photodetectors become crucial components for modern optoelectronic information sensing and communication systems. This study presents an advanced self-powered MXene/GaN Schottky ultraviolet photodetector that features a high-quality van der Waals interface to enhance photoresponsivity. The photodetector exhibits a high responsivity of 681.6 mA W−1 and a significant detectivity of 7.65 × 1013 Jones at zero bias. In a self-powered mode, the detector can operate robustly even under dim illumination (0.15 μW cm−2) due to the excellent Schottky contact and low amount of defect states at the MXene/GaN interface, which presents a strong intrinsic electric field. The photodetector has a high ultraviolet/visible rejection ratio (R360 nm/R400 nm) of 3.9 × 103 and a signal to noise ratio (SNR) of 2.4 × 105, which enable discrimination against visible light interference in real-world scenarios. We also demonstrated that the photodetectors worked well as ultraviolet signal receivers in an optical information communication system to accurately recognize pulsed signals transmitted from an ultraviolet light-emitting diode. These findings imply the great potential of van der Waals Schottky junctions between 2D MXenes and III-nitrides for high-performance photodetection and sensing in many integrated optoelectronic platforms.