Growth and electrical transport properties of organic semiconductor thin films

摘要

Hexadecafluorophthalocyanine (F_(16)CuPc) and Cobalt phthalocyanone (CoPc) thin films of different thickness (20-200nm) have been grown by Molecular Beam Epitaxy (MBE) using different deposition rate (0.2 - 1.0 A/s). For nanowire type growth lower deposition rate and for films of smooth surface higher deposition rate are found suitable. Charge transport (J～V) of CoPc and F_(16)CuPc films is governed by bulk-limited processes with a bias dependent crossover from Ohmic to trap-free space-charge-limited conduction. The mobility (μ) values at 300 K were found 4.5 and 5.5 cm~2 V~(-1) s~(-1) for CoPc and F_(16)CuPc films respectively. Mechanism of reverse rectification behavior of an organic heterojunction comprising of CoPc and F_(16)CuPc is explained by Kelvin Probe measurement.