Electrical characteristics of Al/polyindole Schottky barrier diodes. I. Temperature dependence

In this study, the forward and reverse bias current–voltage ( I – V ), capacitance–voltage ( C – V ), and conductance–voltage ( G /ω– 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 Φ B 0 ( I – V ), ideality factor ( n ), ac electrical conductivity (σ 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 an 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 inhomogeneities and interface states that present at the Al/PIN interface. The conductivity data obtained from G /ω V measurements over a wide temperature range were fitted to the Arrhenius and Mott equations and observed linear behaviors for σ ac vs. 1/ T and ln σ 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 × 10 7 and 1.08 × 10 7 Scm −1 K 1/2 , respectively. Assuming a value of 6 × 10 12 s −1 for ν 0 , the decay length α −1 and the density states at the Fermi energy level, N ( E F ) are estimated to be 8.74 Å and 1.27 × 10 20 eV −1 cm −3 , respectively. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009