The electronic properties of amporphous solids are largely determined by the distributions of localized states N(ε) in the mobility gap. In this experiment, the field effect technique is applied to the experimental study of N(ε) of a-Si prepared by DC glow discharge method. For obtaining N(ε) from field effect data, iterative computer method is used. The density of states at Fermi level was obtained as $6\times10^{17}eV^{-1}cm^{-3}$ when the substrate temperature was 300℃ and the charging effect in the insulator was also found.
