Organic heterojunction and its application for double channel field-effect transistors

Heterojunction organic field-effect transistor (OFET) based on p-type copper phthalocyanine (CuPc) and n-type hexadecafluorophthalocyaninatocopper (F16CuPc) was demonstrated. The heterojunction OFETs can be operated in normally-on (depletion-accumulation) mode, which attributes to the existence of a new conductive channel at the interface of heterojunction. The new channel is originated from accumulation of electrons and holes induced by the interface dipole. Compared with the device with CuPc single layer, the double channel transistor displays improved field-effect mobility from 0.017 to 0.042 cm(2)/V s, and threshold voltage shifts from -17 to +19 V. In addition, ambipolar electric characteristics have been observed from the heterojunction OFETs. (c) 2005 American Institute of Physics.