title: High-performance few-layer Mo-doped ReSe₂ nanosheet photodetectors.
abstract: Transition metal dichalcogenides (TMDCs) have recently been the focus of extensive research activity owing to their fascinating physical properties. As a new member of TMDCs, Mo doped ReSe2 (Mo:ReSe2) is an octahedral structure semiconductor being optically biaxial and highly anisotropic, different from most of hexagonal layered TMDCs with optically uniaxial and relatively high crystal symmetry. We investigated the effects of physisorption of gas molecule on the few-layer Mo:ReSe2 nanosheet based photodetectors. We compared the photoresponse of the as-exfoliated device with annealed device both in air or ammonia (NH3) environment. After annealing at sub-decomposition temperatures, the Mo:ReSe2 photodetectors show a better photoresponsivity (~55.5 A/W) and higher EQE (10893%) in NH3 than in air. By theoretical investigation, we conclude that the physisorption of NH3 molecule on Mo:ReSe2 monolayer can cause the charge transfer between NH3 molecule and Mo:ReSe2 monolayer, increasing the n-type carrier density of Mo:ReSe2 monolayer. The prompt photoswitching, high photoresponsivity and different sensitivity to surrounding environment from the few-layer anisotropic Mo:ReSe2 can be used to design multifunctional optoelectronic and sensing devices.
authors: State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of SciencesP.O. Box 912, Beijing 100083, China.
authors: Shengxue
authors: S
authors: Yang
authors: School for Engineering of Matter, Transport and Energy, Arizona State University, Tempe, AZ 85287, United States.
authors: Sefaattin
authors: S
authors: Tongay
authors: College of Science, National University of Defense Technology, Changsha 410073, China.
authors: Qu
authors: Q
authors: Yue
authors: State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of SciencesP.O. Box 912, Beijing 100083, China.
authors: Yongtao
authors: Y
authors: Li
authors: State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of SciencesP.O. Box 912, Beijing 100083, China.
authors: Bo
authors: B
authors: Li
authors: State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of SciencesP.O. Box 912, Beijing 100083, China.
authors: Fangyuan
authors: F
authors: Lu