Redox Properties of Mixed Methyl/Vinylferrocenyl Monolayers on Si(111) Surfaces
Abstract
We report the redox properties of Si(111) surfaces functionalized with a mixed monolayer of vinylferrocenyl and methyl moieties that have been characterized using spectroscopic, electrical, and electrochemical techniques. The silicon was functionalized using reaction conditions analogous to those of hydrosilylation, but instead of a H-terminated Si surface, a chlorine-terminated Si precursor surface was used to produce the linked vinyl-modified functional group. The functionalized surfaces were characterized by time-resolved photoconductivity decay, X-ray photoelectron spectroscopy, electrochemical measurements, and photoelectrochemical measurements. The functionalized Si surface was well passivated, exhibited high surface coverage and few remaining reactive Si atop sites, had a very low surface recombination velocity, and displayed little initial surface oxidation. The surface was stable toward atmospheric and electrochemical oxidation. The surface coverage of vinylferrocene (or fluorostyrene) was controllably varied from 0 up to 30% of a monolayer. Interfacial charge transfer to the attached ferrocene group was relatively rapid, and a photovoltage of 0.4 V was generated upon illumination of functionalized n-type silicon surfaces in CH_(3)CN.
Additional Information
© 2013 American Chemical Society. Received: October 7, 2013; revised: November 27, 2013; published: December 2, 2013. We thank Dr. James Blakemore for helpful discussions, Dr. Leslie O'Leary for training in silicon surface modification and discussions, and Joseph Beardslee and Dr. Ron Grimm for assistance with the instrumentation. This work was supported by the NSF Powering the Planet Center for Chemical Innovation (CHE-1305124), the National Science Foundation (CHE-1214152), and the Molecular Materials Research Center of the Beckman Institute at the California Institute of Technology.Attached Files
Supplemental Material - jp409958c_si_001.pdf
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Additional details
- Eprint ID
- 43700
- Resolver ID
- CaltechAUTHORS:20140206-113901424
- NSF
- CHE-1305124
- NSF
- CHE-1214152
- Caltech Beckman Institute
- Created
-
2014-02-07Created from EPrint's datestamp field
- Updated
-
2021-11-10Created from EPrint's last_modified field
- Caltech groups
- Kavli Nanoscience Institute, CCI Solar Fuels