GaP-ZnS Multilayer Films : Visible-Light Photoelectrodes by Interface Engineering

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

2 Scopus Citations
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Author(s)

  • Collin K. Park
  • Paria S. M. Gharavi
  • Fran Kurnia
  • Qi Zhang
  • Cui Ying Toe
  • Mohammed Al-Farsi
  • Neil L. Allan
  • Yin Yao
  • Lin Xie
  • Jiaqing He
  • Nagarajan Valanoor
  • Judy N. Hart

Detail(s)

Original languageEnglish
Pages (from-to)3336-3342
Journal / PublicationJournal of Physical Chemistry C
Volume123
Issue number6
Online published17 Jan 2019
Publication statusPublished - 14 Feb 2019
Externally publishedYes

Abstract

In the field of solar water splitting, searching for and modifying bulk compositions have been the conventional approaches to enhancing visible-light activity. In this work, manipulation of heterointerfaces in ZnS-GaP multilayer films is demonstrated as a successful alternative approach to achieving visible-light-active photoelectrodes. The photocurrent measured under visible light increases with the increasing number of interfaces for ZnS-GaP multilayer films with the same total thickness, indicating it to be a predominantly interface-driven effect. The activity extends to long wavelengths (650 nm), much longer than those expected for pure ZnS and also longer than those previously reported for GaP. Density functional theory calculations of ZnS-GaP multilayers predict the presence of electronic states associated with atoms at the interfaces between ZnS and GaP that are different from those found within the layers away from the interfaces; these states, formed due to unique bonding environments found at the interfaces, lead to a lowering of the band gap and hence the observed visible-light activity. The presence of these electronic states attributed to the interfaces is confirmed by depth-resolved X-ray photoelectron spectroscopy. Thus, we show that interface engineering is a promising route for overcoming common deficiencies of individual bulk materials caused by both wide band gaps and indirect band gaps and hence enhancing visible-light absorption and photoelectrochemical performance.

Citation Format(s)

GaP-ZnS Multilayer Films : Visible-Light Photoelectrodes by Interface Engineering. / Park, Collin K.; Gharavi, Paria S. M.; Kurnia, Fran; Zhang, Qi; Toe, Cui Ying; Al-Farsi, Mohammed; Allan, Neil L.; Yao, Yin; Xie, Lin; He, Jiaqing; Ng, Yun Hau; Valanoor, Nagarajan; Hart, Judy N.

In: Journal of Physical Chemistry C, Vol. 123, No. 6, 14.02.2019, p. 3336-3342.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review