TRAPPING EFFECTS IN A-SI-H INVESTIGATED BY THE SSPG TECHNIQUE

The use of the SSPG method at different electric fields and background light intensities yields values of the differential electron drift mo bility. From the dependence of these values on the electron quasi-Ferm i level, as determined by the background illumination, information abo ut the shape of the density of states al approximately 0.4 eV below th e conduction band edge was obtained. The density of states near that e nergy falls off much more slowly towards midgap than near the mobility edge.