J. Phys. Colloques
Volume 42, Numéro C4, Octobre 1981Proceedings of the Ninth International Conference on Amorphous and Liquid Semiconductors
|Page(s)||C4-443 - C4-446|
J. Phys. Colloques 42 (1981) C4-443-C4-446
XEROGRAPHIC SPECTROSCOPY OF LOCALIZED ELECTRONIC STATES IN AMORPHOUS SEMICONDUCTORSM. Abkowitz and R.C. Enck
Xerox Corporation, 800 Phillips Road - 114, Webster, N.Y. 14580, U.S.A.
Analysis of the temperature dependent decay of surface voltage on an amorphous film after charging but prior to exposure (xerographic dark decay) and of residual decay after exposure can in combination be used to map the density of states and position the Fermi level. The procedure is illustrated for a-Se where both electron and hole residuals can be measured. a-Se is found to be characterized by relatively discrete gap state structure. These measurements readily discern thermostructural and photostructural effects on gap state populations. Thus during structural relaxation of glassy films in the As : Se alloy system systematic variation in number of localized states distributed throughout the mobility gap are observed. This observation is consistent with the view that native defects play a key role in photoelectronic behavior of amorphous chalcogenides.