NATURE OF VALENCE STATES OF A-SI1-XCX-H ALLOYS IN THE LOW-CARBON CONCENTRATION LIMIT

It is shown that the local density of states in a Si1-xCx:H can be investigated by combining information from Auger effect, which is site specific, with those from photoemission spectra. In the diluted C regime, it is found that the C centered states with dominant s-like character are localized and lie below the bottom of the dominant Si-Si valence band. The onset of the C centered states with dominant p-like character is placed below the top of the Si valence band. This last result shows that carbon atoms act as strong scattering centers for holes.