Charge Transport and Kelvin Probe Study of Organic Semiconductor Hetero-junction

摘要

We have synthesized organic hetero-junction comprising of n-type copper hexadecafluorophthalocyanine (F_(16)CuPc) / p-type cobalt phthalocyanine (CoPc) using molecular beam epitaxy (MBE). The current - voltage (J-V) characteristics of hetero-junction are ohmic in the entire bias range (0-100 V), while individual films shows a transition from ohmic to space charge limited conduction with increasing bias. Hetero-junction shows one order of magnitude higher current density than individual F_(16)CuPc and CoPc films, indicating the formation of a charge accumulation layers at the interface. The thickness of charge accumulation regions was found to be ～16 nm using Kelvin Probe (KP) method.