Abstract
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 GaInP2 deposited on a thick (5000 A) p-GaAs epilayer. The thin GaInP2 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.
Original language | American English |
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Pages (from-to) | 7871-7874 |
Number of pages | 4 |
Journal | Journal of Physical Chemistry |
Volume | 99 |
Issue number | 20 |
DOIs | |
State | Published - 1995 |
Externally published | Yes |
NREL Publication Number
- NREL/JA-453-7496