Kinetics of the persistent photocurrent in semiconductors: a case example for amorphous chalcogenides |
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Authors: | R. J. Freitas K. Shimakawa T. Wagner |
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Affiliation: | 1. Department of Electrical and Electronic Engineering, National University of Timor Lorosa’e, Dili, East Timor;2. Department of General and Inorganic Chemistry, University of Pardubice, Pardubice, Czech Republic;3. Department of Electrical and Electronic Engineering, Gifu University, Gifu, Japan |
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Abstract: | Although the persistent photocurrent or the residual photocurrent decay (RPD) in photoconductive semiconductors is known to be dominated by dispersive recombination kinetics which produce the stretched exponential functional decay, exp(-Ctβ), where β (<1.0) is the dispersion parameter, the reason for the occurrence of the RPD is still not clear. We discuss the origin of the dispersive nature of long-term photocurrent decay in amorphous chalcogenides (a-Chs) as a case example. The slow recombination path of excess photocarriers in a-Chs can be attributed to their characteristic feature of negative-U defects at which lattice relaxation with multiphonon process may play a role. |
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Keywords: | Amorphous semiconductors persistent photocurrent residual photocurrent decay dispersive recombination kinetics chalcogenides negative-U defects |
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