van der Waals Complementary Barrier Infrared Detector
Xiangbao Xu, Jie Chen, Haitao Wu, Dezheng Guo, Jialin Li, Songsong Zhang, Yunlong Xiao, Ke Deng, Ting He, Hailu Wang, Zhen Wang, Fang Wang, Fang Zhong, Peng Wang, Qing Li, Weida Hu
Abstract
Infrared photodetectors have garnered significant attention in modern optoelectronics due to various applications. However, uncooled infrared photodetectors based on narrow-bandgap materials suffer from high dark current arising from thermal carrier excitation, posing a major challenge in achieving state-of-the-art infrared photodetectors with a blackbody response. In this work, we propose a van der Waals (vdW) complementary barrier infrared detector (CBD), which is composed of an electron barrier from gold/black phosphorus (Au/BP) Schottky contact and a hole barrier from molybdenum disulfide (MoS 2 ). The device effectively suppresses the diffusion dark current, achieving a low dark current of 0.1 μA at −0.1 V. Furthermore, the device demonstrates excellent infrared response with gate-tunable characteristics, exhibiting a peak detectivity of 8.37 × 10 9 cm Hz 1/2 W –1 under blackbody radiation at room temperature. Additionally, the CBD shows strong infrared polarization detection with an anisotropy ratio of 13.9 and exhibits sensitive nondispersive infrared (NDIR) gas detection capability, with a detection limit for methane (CH 4 ) as low as 23.9 ppm. This work provides a promising strategy for the design of room-temperature high-performance vdW infrared photodetectors.