Defect engineering of ZnS thin films for photoelectrochemical water-splitting under visible light

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

34 Scopus Citations
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Author(s)

  • Fran Kurnia
  • Yun Hau Ng
  • Rose Amal
  • Nagarajan Valanoor
  • Judy N. Hart

Detail(s)

Original languageEnglish
Pages (from-to)179-185
Journal / PublicationSolar Energy Materials and Solar Cells
Volume153
Online published6 May 2016
Publication statusPublished - Aug 2016
Externally publishedYes

Abstract

Efficient hydrogen production from water by photocatalysis under sunlight requires a significant improvement in light-harvesting capability. Zinc sulfide is a promising, inexpensive hydrogen generation photocatalyst, but in its pure, bulk form it is only active under ultra-violet light. Here, we show clear evidence of photoelectrochemical activity of ZnS thin films under visible-light irradiation without any co-catalysts, achieved through defect engineering. Fabrication of nanostructured ZnS under controlled conditions introduces defects, and hence intermediate electronic states within the band gap, which allow significant absorption of light at energies below the band gap energy of pure, bulk ZnS. The measured band gap of the ZnS thin films is ~2.4 eV, while the photocurrent density exceeds 1.5 mA/cm2 under visible-light irradiation (λ≥435 nm). This is the first measurement of such high photocurrents for undoped ZnS under visible light.

Research Area(s)

  • Defects, Photocatalysis, Photoelectrochemistry, Thin films, Zinc sulfide