This investigation focuses on the preparation of polypyrrole composite films, Ppy/Al2O3/Al, used as solid-state capacitor with electrochemical polymerization in the presence of DBSA, co-dopant and co-solvent. The parameters of the solid-state capacitor, i.e. leakage current (Lc), capacitor (Cs), dicipation factor (DF) and equivalent series resistance (ESR), were measured in this study. The surface morphology and compositions of the prepared Ppy/Al2O3/Al electrolyte were examined using SEM and EDS, respectively. Further, for 3 C of electricity passed, the values of Lc, Cs, DF and ESR of the Ppy/Al2O3/Al capacitor prepared with 2-NSNa and DBSA as a co-dopant were measured to be 0.029 +/- 0.005 mu A cm(-2), 688.8 +/- 8.28 nF cm(-2), 14.35 +/- 5.63% and 18.63 +/- 3.48 Omega. Further, the parameters both of R-ox and R-ppy are 135.5 and 7.047 Omega. (C) 2007 Elsevier B.V. All rights reserved.