Comparison between the electrical junction properties of H-terminated and methyl-terminated individual Si microwire/polymer assemblies for photoelectrochemical fuel production
Abstract
The photoelectrical properties and stability of individual p-silicon (Si) microwire/polyethylenedioxythiophene/polystyrene sulfonate:Nafion/n-Si microwire structures, designed for use as arrays for solar fuel production, were investigated for both H-terminated and CH_3-terminated Si microwires. Using a tungsten probe method, the resistances of individual wires, as well as between individual wires and the conducting polymer, were measured vs. time. For the H-terminated samples, the n-Si/polymer contacts were initially rectifying, whereas p-Si microwire/polymer contacts were initially ohmic, but the resistance of both the n-Si and p-Si microwire/polymer contacts increased over time. In contrast, relatively stable, ohmic behavior was observed at the junctions between CH_3-terminated p-Si microwires and conducting polymers. CH_3-terminated n-Si microwire/polymer junctions demonstrated strongly rectifying behavior, attributable to the work function mismatch between the Si and polymer. Hence, a balance must be found between the improved stability of the junction electrical properties achieved by passivation, and the detrimental impact on the effective resistance associated with the additional rectification at CH_3-terminated n-Si microwire/polymer junctions. Nevertheless, the current system under study would produce a resistance drop of ~20 mV during operation under 100 mW cm^(−2) of Air Mass 1.5 illumination with high quantum yields for photocurrent production in a water-splitting device.
Additional Information
© 2012 The Royal Society of Chemistry. Received 8th August 2012, Accepted 24th September 2012. First published on the web 25 Sep 2012. Financial support from the Natural Sciences and Engineering Research Council (NSERC) of Canada, the Canada Foundation for Innovation (CFI), the Manitoba Research and Innovation Fund, and the University of Manitoba is gratefully acknowledged. The work reported made use of surface characterization infrastructure in the Manitoba Institute for Materials. This work was supported by a National Science Foundation (NSF) Center for Chemical Innovation (CCI) Powering the Planet (grants CHE-0802907, CHE-0947829, and NSF-ACCF) and made use of the Molecular Materials Research Center of the Beckman Institute at Caltech and the Kavli Nanoscience Institute at Caltech. This research was undertaken, in part, thanks to funding from the Canada Research Chairs Program. S. A. acknowledges partial support from a U. S. Department of Energy, Office of Energy Efficiency and Renewable Energy (EERE) Postdoctoral Research Award under the EERE Fuel Cell Technologies Program.Attached Files
Published - c2ee23115h.pdf
Supplemental Material - c2ee23115h_si.pdf
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Additional details
- Eprint ID
- 36198
- Resolver ID
- CaltechAUTHORS:20130107-103859564
- Natural Sciences and Engineering Research Council of Canada (NSERC)
- Canada Foundation for Innovation
- Manitoba Research and Innovation Fund
- University of Manitoba
- NSF
- CHE-0802907
- NSF
- CHE-0947829
- Department of Energy (DOE)
- Created
-
2013-01-07Created from EPrint's datestamp field
- Updated
-
2021-11-09Created from EPrint's last_modified field
- Caltech groups
- CCI Solar Fuels, Kavli Nanoscience Institute