Transparent thin-film transistors with pentacene channel, AlOx gate, and NiOx electrodes -: art. no. 123505

We report on the fabrication of pentacene-based transparent thin-film transistors (TTFT) that consist of NiOx, AlOx, and indium-tin-oxide (ITO) for the source-drain (S/D) electrode, gate dielectric, and gate electrode, respectively. The NiOx S/D electrodes of which the work function is well matched to that of pentacene were deposited on a 50-nm-thick pentacene channel by thermal evaporation of NiO powder and showed a moderately low but still effective transmittance of similar to 25% in the visible range along with a good sheet resistance of similar to 60 Omega/square. The maximum saturation current of our pentacene-based TTFT was about 15 mu A at a gate bias of -40 V showing a high field effect mobility of 0.9 cm(2)/Vs in the dark, and the on/off current ratio of our TTFT was about 5x10(5). It is concluded that jointly adopting NiOx for the S/D electrode and AlOx for gate dielectric realizes a high-quality pentacene-based TTFT. (C) 2005 American Institute of Physics.