The interface of GaP(100) and H_2O studied by photoemission and reflection anisotropy spectroscopy
Abstract
We study the initial interaction of adsorbed H_2O with P-rich and Ga-rich GaP(100) surfaces. Atomically well defined surfaces are prepared by metal-organic vapour phase epitaxy and transferred contamination-free to ultra-high vacuum, where water is adsorbed at room temperature. Finally, the surfaces are annealed in vapour phase ambient. During all steps, the impact on the surface properties is monitored with in situ reflection anisotropy spectroscopy (RAS). Photoelectron spectroscopy and low-energy electron diffraction are applied for further in system studies. After exposure up to saturation of the RA spectra, the Ga-rich (2 × 4) surface reconstruction exhibits a sub-monolayer coverage in form of a mixture of molecularly and dissociatively adsorbed water. For the p(2 × 2)/c(4 × 2) P-rich surface reconstruction, a new c(2 × 2) superstructure forms upon adsorption and the uptake of adsorbate is significantly reduced when compared to the Ga-rich surface. Our findings show that microscopic surface reconstructions of GaP(100) greatly impact the mechanism of initial interface formation with water, which could benefit the design of e.g. photoelectrochemical water splitting devices.
Additional Information
© 2013 Institute of Physics. Received 22 May 2013. Published 7 October 2013. The authors thank Abdelkrim Chemseddine for valuable discussions and Wolf-Dietrich Zabka for experimental assistance. MMM acknowledges a scholarship from Studienstiftung des deutschen Volkes. Part of this work was supported by the German Research Foundation (DFG, project no. HA 3096/4).Attached Files
Published - 1367-2630_15_10_103003.pdf
Submitted - 1305.5815v2.pdf
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Additional details
- Eprint ID
- 42219
- Resolver ID
- CaltechAUTHORS:20131104-105944560
- Studienstiftung des deutschen Volkes
- HA 3096/4
- Deutsche Forschungsgemeinschaft (DFG)
- Created
-
2013-11-04Created from EPrint's datestamp field
- Updated
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2022-07-12Created from EPrint's last_modified field
- Caltech groups
- JCAP