Organic solvents as gate media for thin-film transistors

Here, we show that some organic solvents can act as electric double layer (EDL) gate media for thin film transistors (TFTs), in a similar way to solid electrolytes, ionic liquids, and water. The ability to act as gate medium is a property of the solvent, not a property of the semiconductor used in the TFT. Only solvents that are fully miscible with water can act as a gate media. However, the ability to undergo autoprotolysis is not an essential property of a gate medium. The most likely explanation for the ability of water-miscible solvents to act as EDL gate media is the inevitable presence of trace amounts of dissolved salts. Because of its large electrochemical window, and aprotic character, acetonitrile is particularly attractive as an alternative gate medium. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4768203]