Electronic conduction in silicon phthalocyanine thin films

Si-Phthalocyanines (SiPc) thin films were deposited on conductive substrates and their electronic properties were studied in sandwich-like Metal-SiPc-Metal structures. The current-voltage characteristics at different temperatures were determined. Aluminum and gold were used as electrode metals. For the Au-SiPc-Au structures, the J-V results were interpreted by using the space-charge-limited-conductivity theory and subsequently the trap density and hole mobility in the SiPc volume were determined. For the Al-SiPc-Al structure the J-V curves were analyzed based on the Schottky theory and the barrier height value for the Al-SiPc barrier was calculated. Moreover, the current density level flowing through the structure was depending on the polarization (forward o reverse) applied to the structure. This effect was attributed to the possible existence of an oxide at the interface between the top electrode and the SiPc.