Effect of thickness of poly(methyl methacrylate) gate dielectric on the performance of pentacene-based organic field-effect transistors

Pentacene-based organic field effect transistors(OFETs) using various thicknesses of poly(methyl methacrylate)(PMMA) as gate dielectric have been fabricated.The dielectric properties of PMMA layer are investigated and the effects of the insulator thickness on the performance of the devices are analyzed in detail.The OFET devices based on 260 nm-thick PMMA gate dielectric exhibit preferable performance and possess a field-effect mobility of 3.39×10-3 cm2/Vs,a threshold voltage of-19 V,and an on/off current ratio of 103.