In this study, the forward and reverse bias current-voltage (I-V), capacitance-voltage (C-V), and conductance-voltage (G/omega-V) characteristics of Al/polyindole (Al/PIN) Schottky barrier diodes (SBDs) were Studied over a wide temperature range of 140-400 K. Zero-bias barrier height Phi(B0)(I-V), ideality factor (n), ac electrical conductivity (sigma(ac)), and activation energy (E-a), determined by using thermionic emission (TE) theory, were shown fairly large temperature dispersion especially at lower temperatures due to surface states and series resistance of Al/PIN SBD. I-V characteristics of the Al/PIN SBDs showed all almost rectification behavior, but the reverse bias saturation current (I-0) and n were observed to be high. This high value of n has been attributed to the particular distribution of barrier heights due to barrier height in homogeneities and interface states that present at the Al/PIN interface. The conductivity data obtained from G/omega V measurements over a wide temperature range were fitted to the Arrhenius and Mott equations and observed linear behaviors for sigma(ac) vs. 1/T and In sigma(ac) vs. 1/T-1/4 graphs, respectively. The Mott parameters of T-0 and K-0 values were determined from the slope and intercept of the straight line as 3.8 x 10(7) and 1.08 x 10(7) Scm(-1) K-1/2, respectively. Assuming a value of 6 x 10(12) s(-1) for v(0), the decay length of alpha(-1) and the density states at the Fermi energy level, N(E-F) are estimated to be 8.74 angstrom and 1.27 x 10(20) eV(-1) cm(-3), respectively. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 113: 2955-2961, 2009