Photoinduced valley-polarized current of layered MoS2 by electric tuning
arXiv:1701.01520 · doi:10.1088/0957-4484/27/18/185202
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.
References in corpus (8)
- Two Dimensional Atomic Crystals
- Valley polarization in MoS2 monolayers by optical pumping
- Valley filter and valley valve in graphene
- Valley Dependent Optoelectronics from Inversion Symmetry Breaking
- Intrinsic and Rashba Spin-orbit Interactions in Graphene Sheets
- Spin-orbit gap of graphene: First-principles calculations
- Electron-hole transport and photovoltaic effect in gated MoS2 Schottky junctions
- Electronic properties of graphene: a perspective from scanning tunneling microscopy and magneto-transport