以n型高掺杂硅为衬底,二氧化硅(SiO2)作绝缘层,钛/金(Ti/Au)双层膜为源漏电极层,真空蒸发酞菁铜(CuPc)作敏感层,制备了沟道宽长比为4000/25的有机薄膜晶体管气体传感器(OTFTs),研究了CuPc-OTFT气体传感器的基本电学特性及其在常温下对有毒还原型气体(H2S和NH3)的敏感性能。结果表明,基于CuPc的OTFT器件具有良好的电学特性,阈值电压为-8 V,载流子迁移率2.47×10-4cm2/V.s,开关电流比5。基于CuPc薄膜的OTFT气体传感器对不同浓度的H2S和NH3均具有较好的响应,对SO2气体响应较小,对CH4和H2几乎不响应。通过CuPc薄膜的紫外-可见光光谱和OTFT器件的转移特性曲线对CuPc-OTFT气体传感器的敏感机理进行了分析。
The Organic Thin Film Transistors(OTFTs) with the ratio of channel width to length as 4000/25 were fab-ricated.N-high doping silicon and the silicon dioxide(SiO2) were used as the substrate and the insulator layer,respectively,and Ti/Au bilayer were taken as the source and drain electrodes.The copper phthalocyanine(CuPc) was vacuum-deposited as the sensing layer.The electrical characteristics and the sensing properties of the CuPc-OTFT sensor were investigated when exposed to the poisonous reducing gas(H2S and NH3) at room temperature.The results showed that CuPc-OTFT possessed good electronic characteristics.The threshold voltage reached-8V,the carrier mobility reached 2.47×10-4 cm2/ V?s and the on/off current ratio(Ion/Ioff) was 5.And the prepared sensor exhibited highly sensitive to H2S and NH3,moder-ately sensitive to SO2,and nearly insensitive to CH4 and H2.The gas-sensing mechanism of CuPc-OTFT gas sensor was further analyzed by the UV-Vis absorption spectra of sensitive films and the transfer curve of sensors.