Ideal behavior at illuminated semiconductor-liquid junctions
- National Renewable Energy Lab., Golden, CO (United States)
Photocurrent-voltage characteristics that show a nearly ideal dependence on the concentration of a nonadsorbed, outer-sphere redox acceptor (cobaltocenium) have been achieved with a novel photoelectrode structure that consists of a thin (30-50 A) epilayer of GaInP{sub 2} deposited on a thick (5000 A) p-GaAs epilayer. The thin GaInP{sub 2} layer produces nearly perfect passivation of the GaAs surface (resulting in a surface recombination velocity <200 cm/s), while at the same time permitting efficient electron transfer via field-assisted tunneling and/or thermionic emission. The electron transfer kinetics, as characterized by quenching of the GaAs photoluminescence, also shows a systematic acceptor concentration dependence. An unambiguous concentration dependence of the photocurrent and electron transfer kinetics has not been previously reported at semiconductor-liquid junctions. 21 refs., 4 figs.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 62295
- Journal Information:
- Journal of Physical Chemistry, Journal Name: Journal of Physical Chemistry Journal Issue: 20 Vol. 99; ISSN JPCHAX; ISSN 0022-3654
- Country of Publication:
- United States
- Language:
- English
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