1. PN/PAs-WSe2 van der Waals heterostructures for solar cell and photodetector.
- Author
-
Zheng, Xinyi, Wei, Yadong, Pang, Kaijuan, Kaner Tolbert, Ngeywo, Kong, Dalin, Xu, Xiaodong, Yang, Jianqun, Li, Xingji, and Li, Weiqi
- Subjects
P-type semiconductors ,BAND gaps ,VAN der Waals forces ,SOLAR cells ,EXCITON theory ,ELECTRIC fields ,HETEROSTRUCTURES ,PHOTODETECTORS - Abstract
By first-principles calculations, we investigate the geometric stability, electronic and optical properties of the type-II PN-WSe
2 and type-I PAs-WSe2 van der Waals heterostructures(vdWH). They are p-type semiconductors with indirect band gaps of 1.09 eV and 1.08 eV based on PBE functional respectively. By applying the external gate field, the PAs-WSe2 heterostructure would transform to the type-II band alignment from the type-I. With the increasing of magnitude of the electric field, two heterostructures turn into the n-type semiconductors and eventually into metal. Especially, PN/PAs-WSe2 vdWH are both high refractive index materials at low frequencies and show negative refractive index at high frequencies. Because of the steady absorption in ultraviolet region, the PAs-WSe2 heterostructure is a highly sensitive UV detector material with wide spectrum. The type-II PN-WSe2 heterostructure possesses giant and broadband absorption in the near-infrared and visible regions, and its solar power conversion efficiency of 13.8% is higher than the reported GaTe–InSe (9.1%), MoS2 /p-Si (5.23%) and organic solar cells (11.7%). It does project PN-WSe2 heterostructure a potential for application in excitons-based solar cells. [ABSTRACT FROM AUTHOR]- Published
- 2020
- Full Text
- View/download PDF