Charge Carrier Transport in p-sexiphenyl Thin Films

In this paper the results of DC conductivity measurements done for p-sexiphenyl polycrystalline thin films are presented. The investigations concerned the influence of the crystalline structure on charge carrier transport depending on several parameters, such as temperature, film thickness, electric field intensity and electrodes polarization. The measured current gives information on the quantity of charge flowing through the thin film volume. Additionally, charge drift mobility was measured, its character was determined and molecular dynamics simulations were performed. In the simulations the participation of crystalline and amorphous phases were taken into account, as well as a transition phase at the crystal-amorphous phase boundary. The obtained results were compared with the experimental data. The DC conductivity activation energy value was found to be in the range of 0.008-1.0 eV. The thickness of the investigated layers varied from 0.2 to 2.5 mu m, and the applied electric fields and temperatures changed from 0 to 2.10(7) V/m and from 15 to 325 K, respectively.