Transport and Photoelectric Properties of 2D Silicene/MX2 (M = Mo, W; X = S, Se) Heterostructures

Yuxiu Wang; Rui Qi; Yingjie Jiang; Cuicui Sun; Guiling Zhang; Yangyang Hu; Zhao-Di Yang; Weiqi Li

doi:10.1021/acsomega.8b01282

Transport and Photoelectric Properties of 2D Silicene/MX₂ (M = Mo, W; X = S, Se) Heterostructures

ACS Omega. 2018 Oct 16;3(10):13251-13262. doi: 10.1021/acsomega.8b01282. eCollection 2018 Oct 31.

Authors

Yuxiu Wang¹, Rui Qi¹, Yingjie Jiang¹, Cuicui Sun¹, Guiling Zhang¹, Yangyang Hu¹, Zhao-Di Yang¹, Weiqi Li²

Affiliations

¹ School of Materials Science and Engineering, Harbin University of Science and Technology, Harbin 150080, China.
² Department of Physics, Harbin Institute of Technology, Harbin 150001, China.

Abstract

The transport and photoelectric properties of four two-dimensional (2D) silicene/MX₂ (M = Mo, W; X = S, Se) heterostructures have been investigated by employing density functional theory, nonequilibrium Green's function, and Keldysh nonequilibrium Green's function methods. The stabilities of silicene (SiE) are obviously improved after being placed on the MX₂ (M = Mo, W; X = S, Se) substrates. In particular, the conductivities of SiE/MX₂ are enhanced compared with free-standing SiE and MX₂. Moreover, the conductivities are increased with the group number of X, i.e., in the order of SiE < SiE/MS₂ < SiE/MSe₂. An evident current oscillation phenomenon is observed in the SiE/WX₂ heterostructures. When a linear light illumination is applied, SiE/MSe₂ shows a stronger photoresponse than SiE/MS₂. The maximum photoresponse with a value of 9.0a ₀ ²/photon was obtained for SiE/WSe₂. More importantly, SiE/MS₂ (M = Mo, W) heterostructures are good candidates for application in designing solar cells owing to the well spatial separation of the charge carriers. This work provides some clues for further exploring 2D SiE/MX₂ heterostructures involving tailored photoelectric properties.