Inverted xerographic depletion discharge mechanism for the dark decay of electrostatic surface potential on amorphous semiconductors

Journal Article · Fri Jul 01 00:00:00 EDT 1988 · J. Appl. Phys.; (United States)

DOI:https://doi.org/10.1063/1.341218· OSTI ID:5184631

Kasap, S O

Recently, the xerographic depletion discharge (XDD) model has been applied extensively to chemically modified a-Se, a-Se/sub 1/..sqrt../sub x/Te/sub x/ alloys, and a-As/sub 2/Se/sub 3/ as well as to a-Si:H films to study the nature of charge carrier generation from deep mobility gap states which control the dark decay of the electrostatic surface potential on a corona charged amorphous semiconductor. In the normal XDD model, the dark discharge involves bulk thermal generation of a mobile carrier of the same sign as the surface charge and its subsequent sweep out from the sample leaving behind an ionized center of opposite charge. It is shown that an ''inverted depletion discharge'' mechanism, which involves the thermal generation of a mobile charge carrier of the opposite sign to the surface charge and its subsequent drift to the surface and the resulting surface charge neutralization there, results in a dark discharge rate which has identical features as the normal XDD mechanism. In the normal XDD mechanism, the neutral region develops after the depletion time from the grounded electrode, whereas in the inverted XDD mechanism the neutral region grows from the surface. Furthermore, during inverted depletion discharge the surface charge is actually dissipated by neutralization, whereas in the normal depletion discharge model there is no such requirement over the time scale of the experiment. It is concluded that xerographic dark decay experiments alone cannot determine the sign of the thermally generated mobile carrier and that of the bulk space charge. Chemically modified amorphous selenium case is discussed as an example of surface potential decay resulting from bulk space-charge buildup.

• Research Organization: Department of Electrical Engineering, University of Saskatchewan, Saskatoon, Saskatchewan S7N 0W0, Canada
• OSTI ID: 5184631
• Journal Information: J. Appl. Phys.; (United States), Vol. 64:1
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ARSENIC SELENIDES
CHARGE CARRIERS
SELENIUM ALLOYS
SELENIUM TELLURIDES
SILANES
AMORPHOUS STATE
CARRIER MOBILITY
MATHEMATICAL MODELS
SEMICONDUCTOR MATERIALS
SURFACE POTENTIAL
XEROGRAPHY
ALLOYS
ARSENIC COMPOUNDS
CHALCOGENIDES
HYDRIDES
HYDROGEN COMPOUNDS
MATERIALS
MOBILITY
ORGANIC COMPOUNDS
ORGANIC SILICON COMPOUNDS
POTENTIALS
SELENIDES
SELENIUM COMPOUNDS
SILICON COMPOUNDS
TELLURIDES
TELLURIUM COMPOUNDS
360603* - Materials- Properties