Copper Phthalocyanine and Pentacene Organic Thin-Film Transistor-Structured Ethanol Gas Sensors

In this article, copper phthalocyanine (CuPc) and pentacene double sensing membranes were used in organic thin-film transistor-structured ethanol gas sensors. To study the thickness effect of CuPc layer, various-thick CuPc layers were, respectively, deposited on 50-nm-thick pentacene layer. In addition to the passivation function of the CuPc layer, the performances of the resulting ethanol gas sensors were improved with an increase of the thickness of the CuPc layer until 5 nm and was then degraded with a further increase of its thickness. For the ethanol gas sensors with 50-nm-thick pentacene layer and 5-nm-thick CuPc layer operated at room temperature under 100 ppm ethanol gas concentration, the associated sensitivity was 70%.