An organic thin-film transistor(OTFT) with OTS/SiO2 bilayer gate insulators between gate insulator and source/drain electrodes is investigated.Thermal grown SiO2 layer is used as the OTFT gate dielectric;Zinc phthalocyanine(ZnPc) is used as an active layer.The octadecyltrichlorosilane(OTS) is used to reduce the surface energy of the SiO2 gate dielectric and significantly improve the flat level of the devices.This OTS/SiO2 bilayer gate insulator increases the field-effect mobility by 3.5 times,reduces the le...