Improved Performance of Fluorinated Copper Phthalocyanine Thin Film Transistors Using Para-hexaphenyl as the Inducing Layer

Abstract

We demonstrate n-type organic thin film transistors (OTFTs) employing copper hexadecafluorophthalocyanine (CuPcF16) as the active layer and para-hexaphenyl (p-6p) as the inducing layer. Compared with the CuPcF16-based OTFTs without the p-6p inducing layer, the performance of the CuPcF16/p-6p OTFTs is greatly improved. The charge carrier field-effect mobility μ, on-off current ratio Ion/Ioff and threshold voltage VT of the CuPcF16/p-6p OTFTs are 0.07 cm2/V·s, 1.61 × 105 and 6.28 V, respectively, approaching the level of a single crystal device. The improved performance is attributed to the introduction of p-6p to form a highly oriented and continuous film of CuPcF16 with the molecular π-π stack direction parallel to the substrate.