Effective performance improvement of organic thin film transistors by using tri-layer insulators

Organic thin film transistors (OTFTs) with silicon oxide (SiO2)/poly(4-vinylphenol) (PVP)/polymethylmethacrylate (PMMA) tri-layer structure (SPP) as dielectric layers have been fabricated. To verify the validity of such tri-layer structure, two different organic semiconductor materials such as p-type pentacene and n-type fluorinated copper phthalo-cyanine (F16CuPc) are both used for fabricating OTFTs. Comparing with the OTFTs even by using PMMA modification, the better interface quality existing between SPP dielectric and organic film leads a higher conductive efficiency for transport carriers in channel. And then the field effect carriers (hole in pentacene OTFTs and electron in F16CuPc OTFTs) mobilities are both increased obviously. Our results show the SPP dielectric structure can be widely used to improve performance of OTFTs.