Effect of organic buffer layer on performance of pentacene field-effect transistor fabricated on natural mica gate dielectric

The mobility of pentacene-based organic field-effect transistors (OFETs) fabricated on natural mica substrates has been highly improved using poly (methyl methacrylate) (PMMA) or octadecyltrimethoxysillane (OTMS) as a buffer layer between the mica dielectric and the pentacene active layer. The field-effect mobility increased from 2.4 × 10^-3 to 0.14 or 0.31 cm²·V^-1·s^-1 by inserting the PMMA or OTMS buffer layer, respectively. The suppression of the unfavorable effect of potassium ions using the OTMS buffer layer confirmed the feasibility of using natural mica as a transparent gate dielectric of OFETs.