title: Photoinduced valley-polarized current of layered MoS2 by electric tuning.
abstract: A photoinduced current of a layered MoS2-based transistor is studied from first-principles. Under the illumination of circular polarized light, a valley-polarized current is generated, which can be tuned by the gate voltage. For monolayer MoS2, the valley-polarized spin-up (down) electron current at K (K') points is induced by the right (left) circular polarized light. The valley polarization is found to reach +1.0 (-1.0) for the valley current that carried such a K (K') index. For bilayer MoS2, the spin-up (down) current can be induced at both K and K' valleys by the right (left) circular light. In contrast to monolayer MoS2, the photoinduced valley polarization shows asymmetric behavior upon reversal of the gate voltage. Our results show that the valley polarization of the photoinduced current can be modulated by the circular polarized light and the gate voltage. All the results can be well understood using a simple kp model.
authors.affiliation: College of Physics Science and Technology, and Institute of Computational Condensed Matter Physics, Shenzhen University, Shenzhen 518060, People's Republic of China.
authors.forename: Yunjin
authors.initials: Y
authors.lastname: Yu
authors.forename: Yanfeng
authors.initials: Y
authors.lastname: Zhou
authors.forename: Langhui
authors.initials: L
authors.lastname: Wan
authors.forename: Bin
authors.initials: B
authors.lastname: Wang
authors.forename: Fuming
authors.initials: F
authors.lastname: Xu
authors.forename: Yadong
authors.initials: Y
authors.lastname: Wei
authors.forename: Jian
authors.initials: J
authors.lastname: Wang