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Energy Express

  • Editor: Bernard Kippelen
  • Vol. 20, Iss. S2 — Mar. 12, 2012
  • pp: A190–A196

Immersed finger-type indium tin oxide ohmic contacts on p-GaN photoelectrodes for photoelectrochemical hydrogen generation

Shu-Yen Liu, J. K. Sheu, M. L. Lee, Yu-Chuan Lin, S. J. Tu, F. W. Huang, and W. C. Lai  »View Author Affiliations

Optics Express, Vol. 20, Issue S2, pp. A190-A196 (2012)

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In this study, we demonstrated photoelectrochemical (PEC) hydrogen generation using p-GaN photoelectrodes associated with immersed finger-type indium tin oxide (IF-ITO) ohmic contacts. The IF-ITO/p-GaN photoelectrode scheme exhibits higher photocurrent and gas generation rate compared with p-GaN photoelectrodes without IF-ITO ohmic contacts. In addition, the critical external bias for detectable hydrogen generation can be effectively reduced by the use of IF-ITO ohmic contacts. This finding can be attributed to the greatly uniform distribution of the IF-ITO/p-GaN photoelectrode applied fields over the whole working area. As a result, the collection efficiency of photo-generated holes by electrode contacts is higher than that of p-GaN photoelectrodes without IF-ITO contacts. Microscopy revealed a tiny change on the p-GaN surfaces before and after hydrogen generation. In contrast, photoelectrodes composed of n-GaN have a short lifetime due to n-GaN corrosion during hydrogen generation. Findings of this study indicate that the ITO finger contacts on p-GaN layer is a potential candidate as photoelectrodes for PEC hydrogen generation.

© 2012 OSA

OCIS Codes
(310.3840) Thin films : Materials and process characterization
(310.4925) Thin films : Other properties (stress, chemical, etc.)
(310.6845) Thin films : Thin film devices and applications
(310.7005) Thin films : Transparent conductive coatings

ToC Category:
Solar Fuel

Original Manuscript: November 11, 2011
Revised Manuscript: January 4, 2012
Manuscript Accepted: January 5, 2012
Published: January 11, 2012

Shu-Yen Liu, J. K. Sheu, M. L. Lee, Yu-Chuan Lin, S. J. Tu, F. W. Huang, and W. C. Lai, "Immersed finger-type indium tin oxide ohmic contacts on p-GaN photoelectrodes for photoelectrochemical hydrogen generation," Opt. Express 20, A190-A196 (2012)

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