Quenching Effects and Negative Photoconductivity in Amorphous Selenium

Publisher Website
Google Scholar
Abstract
Negative photoconductivity and long wavelength quenching of photoconductivity have been observed in several evaporated layers of amorphous Se, with both effects showing a maximum for light of energy between 1.9 and 2.1 ev. From the position of the Fermi level, these effects have been identified with transitions from a set of sensitizing centers ranging from less than 0.58 to 0.65 ev above the valence band. Deep traps were investigated by thermally stimulated currents and by the analysis of space charge limited currents. Trapping states at 0.55 ev were detected which probably correspond to the same set of defect levels as the sensitizing centers. Several models which might account for the optical absorption, spectral response, quenching phenomena, and the exponential temperature dependence of the carrier mobilities, are discussed.

This publication has 20 references indexed in Scilit: