High Current-Gain Cutoff Frequencies above 10MHz in n-Channel C-60 and p-Channel Pentacene Thin-Film Transistors

The current-gain cutoff frequencies for bottom contact n-channel C-60 and p-channel pentacene thin-film transistors (TFTs) with channel lengths of 2-10 mu m have been investigated. The cutoff frequency was estimated by direct measurement of the gate and drain modulation currents. The measured cutoff frequencies for both C-60 and pentacene TFTs increase consistently with reducing channel length. Cutoff frequencies of 27.7 and 11.4 MHz were obtained from C-60 and pentacene TFTs with a channel length of 2 mu m, respectively. (C) 2011 The Japan Society of Applied Physics