Ying Xie, Fei Liang, Shumeng Chi, Dong Wang, Kai Zhong, Haohai Yu, Huaijin Zhang, Yanxue Chen, Jiyang Wang
https://pubs.acs.org/doi/10.1021/acsami.9b21671
Two-dimensional (2D) materials have exotic intrinsic electronic band structures and are considered as revolutionary foundations for novel nano-devices. Band engineering of 2D materials may pave a new avenue to overcome numerous challenges in modern technologies, such as room-temperature (RT) photodetection of the light with photon energy below their bandgaps. Here, we reported the pioneered RT MoS2-based photodetection in the terahertz (THz) region via introducing Mo4+ and S2- vacancies for rational bandgap engineering. Both the generation and transport of extra carriers driven by THz electromagnetic radiations, were regulated by the vacancy concentration as well as the resistivity of MoS2 samples. Utilizing the balance between the carrier concentration fluctuation and carrier-scattering probability, a high RT photoresponsivity of 10 mA/W at 2.52 THz was realized in Mo-vacancy rich MoS2.19 sample. This work overcomes the challenge in the excessive dark current of RT THz detection and offers a convenient way for further optoelectronics and photonics devices based on bandgap engineered 2D materials.
