Schottky diodes were prepared by evaporation of Pd onto undoped and phosphorous doped a-Si:H films produced by glow discharge decomposition of $SiH_4$ on the stainless steel substrates. The various diode parameters were determined from J-V measurements and the doping effects on J-V characteristics of diode were examined. The capacitance and conductance were studied as a function of applied bias voltage and modulation frequency. The measured C(ω)-V and G(ω)-V characteristics were qualitatively analyzed in terms of the simplified equivalent circuit model. Finally C(V=o,ω) and G(V=o,ω) derived from general ac equivalent circuit theory were fitted to the experimentally measured data and the density of states at the neighbourhood of Fermi level was obtained.
