Ultralow-voltage transparent electric-double-layer thin-film transistors processed at room-temperature

Electric-double-layer effect is observed in mesoporous SiO2 films deposited by plasma-enhanced chemical vapor deposition at room temperature. Room-temperature processed transparent InGaZnO4 thin film transistors (TFTs) gated with such mesoporous SiO2 dielectric show an ultralow operating voltage of 1.0 V due to the large electric-double-layer capacitance. The InGaZnO4 TFTs exhibit a good performance with a high field-effect mobility of 28.5 cm(2)/V s, a low subthreshold swing of 110 mV/decade, and a large on-off ratio of 1.1 x 10(6), respectively. Such ultralow-voltage devices are very promising for low-power transparent macroelectronics on temperature-sensitive substrates. (C) 2009 American Institute of Physics. [doi:10.1063/1.3251782]