AUGEREMISSION-SPECTROSCOPY AND PHOTOEMISSION-SPECTROSCOPY STUDIES OF THE LOCAL DENSITY OF STATES OF A-SI1-XCX-H ALLOYS AT LOW C-CONCENTRATION

Valence states of a-Si1-xCx:H alloys have been studied by combining photoemission and Auger spectroscopies. It is found that heteronuclear Si-C bonds are strongly favored. The analysis of the Si CVV and C KVV Auger processes shows that relaxation and correlation effects are small in these alloys, with the possible exception of transitions involving electrons in hydrogen bonds, which are localized. By combining information from valence-band energy-distribution curves, core-level, and Auger spectroscopies the relative position of the onsets and of the maxima of the local density of states at C and Si was established.