Electrical Transport Properties of Thermally Evaporated Phthalocyanine (H2Pc) Thin Films

Abstract

Thin films of H 2 Pc of various thicknesses have been deposited onto glass substrates using thermal evaporation technique at room temperature. The dark electrical resistivity calculations were carried out at different temperatures in the range 298-473 K. Measurements of thermoelectric power confirm that H 2 Pc thin films behave as a p-type semiconductor. The current density-voltage characteristics of H 2 Pc at room temperature showed ohmic conduction mechanism at low voltages. At higher voltages the space-chargelimited conduction (SCLC) accompanied by an exponential trap distribution was dominated. The temperature dependence of current density allows determination of some essential parameters such as the hole mobility (µ h), the total trap concentration (N t), the characteristic temperature (T t) and the trap density P (E).