Preprint Article Version 1 This version is not peer-reviewed

Mixed-Phase (2H and 1T) MoS2 Catalyst for a Highly Efficient and Stable Si Photocathode

Version 1 : Received: 31 October 2018 / Approved: 1 November 2018 / Online: 1 November 2018 (18:09:09 CET)

A peer-reviewed article of this Preprint also exists.

Joe, J.; Bae, C.; Kim, E.; Ho, T.A.; Yang, H.; Park, J.H.; Shin, H. Mixed-Phase (2H and 1T) MoS2 Catalyst for a Highly Efficient and Stable Si Photocathode. Catalysts 2018, 8, 580. Joe, J.; Bae, C.; Kim, E.; Ho, T.A.; Yang, H.; Park, J.H.; Shin, H. Mixed-Phase (2H and 1T) MoS2 Catalyst for a Highly Efficient and Stable Si Photocathode. Catalysts 2018, 8, 580.

Journal reference: Catalysts 2018, 8, 580
DOI: 10.3390/catal8120580

Abstract

We describe the direct formation of mixed-phase (1T and 2H) MoS2 layers on Si as a photocathode via atomic layer deposition (ALD) for application in the photoelectrochemical (PEC) reduction of water to hydrogen. Without typical series-metal interfaces between Si and MoS2, our p-Si/SiOx/MoS2 photocathode showed efficient and stable operation in hydrogen evolution reactions (HERs). The resulting performance could be explained by spatially genuine device architectures in three dimensions (that is, laterally homo and vertically heterojunction structures). The ALD-grown MoS2 overlayer with the mixed-phase 1T and 2H homojunction passivates light absorber and surface states and functions as a monolithic structure for effective charge transport within MoS2. It is also beneficial in the operation of p-i-n heterojunctions with inhomogeneous barrier heights due to the presence of mixed-phase cocatalysts. The effective barrier heights reached up to 0.8 eV with optimized MoS2 thicknesses, leading to a 670 mV photovoltage enhancement without employing buried Si p-n junctions. The fast-transient behaviors via light illumination show that the mixed-phase layered chalcogenides can serve as efficient cocatalysts by depinning the Fermi levels at the interfaces. A long-term operation of ~ 70 h was also demonstrated in a 0.5 M H2SO4 solution.

Subject Areas

Photoelectrochemical water splitting; Silicon/MoS2 junction; Atomic Layer Deposition; Mixed-phase metal chalcogenides

Comments (0)

We encourage comments and feedback from a broad range of readers. See criteria for comments and our diversity statement.

Leave a public comment
Send a private comment to the author(s)
Views 0
Downloads 0
Comments 0
Metrics 0


×
Alerts
Notify me about updates to this article or when a peer-reviewed version is published.