Improved Performance of Phthalocyanine Derivative Field-Effect Transistors by Inserting a Para-Quarterphenyl as the Inducing Layer

We investigate the phthalocyanine derivative organic field-effect transistors (OFETs) using a novel para -quaterphenyl (p-4p) as the inducing layer. Compared to the devices without the p-4p inducing layer, the performances of p-type (copper phthalocyanine) and n-type (fluorinated copper phthalocyanine) OFETs with optimized thickness of p-4p thin films are greatly enhanced. Both the field-effect mobility and the on/off ratio of the two-type devices are improved by one order of magnitude compared to those of the control devices. This remarkable improvement is attributed to the introduction of p-4p, which can form a highly oriented and continuous phthalocyanine derivative film with the molecular π–π stack direction parallel to the substrate.