Enhanced Performance of a Monolayer MoS2/WSe2 Heterojunction as a Photoelectrochemical Cathode

Abstract Transition-metal dichalcogenide (TMD) semiconductors have attracted interest as photoelectrochemical (PEC) electrodes due to their novel band-gap structures, optoelectronic properties, and photocatalytic activities. However, the photo-harvesting efficiency still requires improvement. In thi...

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Bibliographic Details
Main Authors: Jingwei Xiao, Yu Zhang, Huanjun Chen, Ningsheng Xu, Shaozhi Deng
Format: Article
Language:English
Published: SpringerOpen 2018-07-01
Series:Nano-Micro Letters
Subjects:
Online Access:http://link.springer.com/article/10.1007/s40820-018-0212-6
Description
Summary:Abstract Transition-metal dichalcogenide (TMD) semiconductors have attracted interest as photoelectrochemical (PEC) electrodes due to their novel band-gap structures, optoelectronic properties, and photocatalytic activities. However, the photo-harvesting efficiency still requires improvement. In this study, A TMD stacked heterojunction structure was adopted to further enhance the performance of the PEC cathode. A P-type WSe2 and an N-type MoS2 monolayer were stacked layer-by-layer to build a ultrathin vertical heterojunction using a micro-fabrication method. In situ measurement was employed to characterize the intrinsic PEC performance on a single-sheet heterostructure. Benefitting from its built-in electric field and type II band alignment, the MoS2/WSe2 bilayer heterojunction exhibited exceptional photocatalytic activity and a high incident photo-to-current conversion efficiency (IPCE). Comparing with the monolayer WSe2 cathode, the PEC current and the IPCE of the bilayer heterojunction increased by a factor of 5.6 and enhanced 50%, respectively. The intriguing performance renders the MoS2/WSe2 heterojunction attractive for application in high-performance PEC water splitting.
ISSN:2311-6706
2150-5551