Analysis of electrical characteristics of high performance pentacene thin-film transistors with PMMA buffer layer

Top contact and bottom contact TFTs, based on evaporated pentacene, have been fabricated by using PMMA as buffer layer. Both type of devices show high performance with field-effect mobility >1 cm2/V s. Top contact transfer characteristics, measured at different temperatures, have been analyzed by the 'temperature method' in order to evaluate the effective density of localized states (DOS). The calculated DOS, approximated by two exponential tails, has been used in 2D numerical device analysis program to simulate the transfer and output characteristics at different temperatures.