Abstract
Substitutional doping was attained by co-sputtering B or P with Si under high Ar gas pressure. Adsorption effects on conductance and ESR were found in doped samples. The changes of conductance and ESR signal due to the adsorption of gases can be consistently explained by the changes of the occupation profile of electrons in the gap states which were caused by electrons or holes donated from adsorbates. Successful substitutional doping and distinct adsorption effects are considered to be due to a relatively small density of localized gap states in those a-Si which were prepared by rf sputtering under high Ar gas pressure.
