Temperature-dependent current-voltage characteristics of poly-N-epoxypropylcarbazole complex

In this study, current-voltage (I-V) characteristics of thin films of poly-N-epoxypropylcarbazole (PEPC) doped with anthracene have been investigated. The PEPC films were grown on nickel substrates, at room temperature, by using a centrifugal machine operated at 277 g. I-V characteristics were then evaluated as a function of temperature ranging from 30 to 60 degrees C. Reversible rectifying characteristics were exhibited by the devices in which current magnitude increases with increasing values of temperature. This has been explained with temperature assisted hopping process of free carriers in the organic film having positional as well as energetic disorders whilst the nonlinear I- V characteristics follow space charge limited current (SCLC) model. By applying the correlated Gaussian disorder mobility model to the experimental SCLC, the energetic disorder parameter and average intersite spacing between hopping locations have been calculated. It has been observed that energetic disorderness and average intersite distance in PEPC complex are relatively higher which could be a cause of low hole mobility in PEPC organic semiconductor. (C) 2007 Elsevier B.V. All rights reserved.