Pentacene field-effect transistor(OFET) was fabricated with silicon oxide(SiO2) or poly-methylmethacrylate(PMMA) as the gate insulator.The SiO2 insulator was fabricated with thermally grown method,and the PMMA was fabricated by solution-casting method.Comparing with traditional OFETs which have inorganic insulator,the transistor with PMMA dielectric can have advantage in easily making films by solution-processing with low cost,and it can improve the performance of transistors obviously.Then,OFET can be oper...