Hou, Y., Yu, X., Syed, Z.A. et al. (3 more authors) (2016) GaN nano-pyramid arrays as an efficient photoelectrode for solar water splitting. Nanotechnology, 27 (45). 455401. ISSN 0957-4484
Abstract
A prototype photoelectrode has been fabricated using a GaN nano-pyramid array structure grown on a cost-effective Si (111) substrate, demonstrating a significant improvement in performance of solar-powered water splitting compared with any planar GaN photoelectrode. Such a nano-pyramid structure leads to enhanced optical absorption as a result of a multi-scattering process which can effectively produce a reduction in reflectance. A simulation based on a finite-difference time-domain approach indicates that the nano-pyramid architecture enables incident light to be concentrated within the nano-pyramids as a result of micro-cavity effects, further enhancing optical absorption. Furthermore, the shape of the nano-pyramid further facilitates the photo-generated carrier transportation by enhancing a hole-transfer efficiency. All these features as a result of the nano-pyramid configuration lead to a large photocurrent of 1 mA cm(-2) under an illumination density of 200 mW cm(-2), with a peak incident photon-to-current conversion efficiency of 46.5% at ∼365 nm, around the band edge emission wavelength of GaN. The results presented are expected to pave the way for the fabrication of GaN based photoelectrodes with a high energy conversion efficiency of solar powered water splitting.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2016 IOP Publishing Ltd. Original content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI |
Keywords: | photoelectrode; water splitting; hydrogen generation; GaN |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Engineering (Sheffield) > Department of Electronic and Electrical Engineering (Sheffield) |
Funding Information: | Funder Grant number ENGINEERING AND PHYSICAL SCIENCE RESEARCH COUNCIL (EPSRC) EP/M015181/1 |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 30 Nov 2016 15:28 |
Last Modified: | 30 Nov 2016 15:28 |
Published Version: | http://doi.org/10.1088/0957-4484/27/45/455401 |
Status: | Published |
Publisher: | IOP Publishing |
Refereed: | Yes |
Identification Number: | 10.1088/0957-4484/27/45/455401 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:108643 |