The current-voltage characteristic of the prepared Al/Polythiophene-SiO2/p-Si Schottky diode was analyzed by using different methods at room temperature. The barrier height and ideality factor of the diode were determined by using the conventional current-voltage method as 0.729 eV and 2.11 respectively. The barrier height values calculated by means of the modified Norde functions have showed good agreement with the barrier height value obtained by using the current-voltage method. The series resistance which causes the electrical characteristics to be non-ideal was calculated from Cheung functions and the modified Norde functions. The energy distribution of the interface states has been determined from the forward-bias current-voltage data. The frequency dependence of the Schottky diode parameters obtained from capacitance-voltage characteristics has been analyzed. (C) 2011 Elsevier B.V. All rights reserved.