Characterization of deep defect levels in amorphous selenium by optical methods

Abstract

In order to determine the energy levels of the naturally existing structural defects in amorphous selenium, measurements of the photoacoustic spectrum, the photoconductivity spectrum and the nearinfrared quenching spectrum of photoconductivity were carried out. These three spectra exhibit a peak at the same energy, 1.43 eV. Detailed investigation into the infrared quenching characteristics suggest that the level of naturally existing positively charged defect state, D +, is located at 1.43 eV above the valence band.