On the energy position of localized defect states and impurity distribuiton in amorphous silicon produced by ion implantation

Photoconduction spectra in amorphous silicon produced with neon and argon ion implantation into a monocrystal substrate have been studied. Optical width of the forbidden zone of ion-implanted a-Si constitutes 1.42 eV. The density of localized states has the form predicted by Mott. A peak of defect states takes place at Esub(v)+0.8 eV. Impurity distribution in a-Si has been studied by means of the Auger electron spectroscopy method. It is established that the implanted neon evaporates from a-Si at room temperature. There is a considerable concentration of oxygen and carbon in a-Si hear-to-surface layer (approximately 150 A)