Role of growth temperature on the frequency response characteristics of pentacene-based organic devices

The ac frequency response characteristics (FRC) of organic thin film transistors and metalinsulator semiconductor diodes were highly improved by controlling the morphology and electrical characteristics of semiconducting pentacene films. The devices with films grown at 50 degrees C show much higher cutoff frequency and better frequency stability of flat-band voltage, as compared to those with films grown at other temperatures below or above. The improvement mainly originates from the maximum field effect carrier mobility of 0.78 cm(2) V-1 s(-1) and a small metal/organic contact resistance (R-c) obtained in the optimum thin film transistors. Our results indicate growth temperature precisely tunes the film microstructure and metal/semiconductor interface, which together determine the FRC of pentacene-based organic devices.