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).