Conduction in lead phthalocyanine thin films with aluminium electrodes

Electronic conduction has been investigated in evaporated lead hthalocyanine thin films with aluminium electrodes. In contrast to previously investigated samples where the injecting electrode was a gold ohmic cont ct, these samples did not exhibit space-charge-limited conductivity, but showed carrier excitation via a field-lowering mechanism with a logJ µ V1/2 current density-voltage (J- V) characteristic. Both polarities showed two regions in the J- V characteristics having different slopes, leading to the conclusion that conduction is via Schottky and Poole-Fr nkel emission at lower and higher voltages respectively. In the presence of air there was a decr ase in conductivity, which was attributed to the effects of oxygen at the electrodes