Highly Efficient Room Temperature DMA and TMA Sensor Based on MoS₂–ZnO Hybrid Channel FET Device

In this paper, a back-gated Field Effect Transistor (FET) sensor with MoS<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub>-ZnO hybrid channel is reported for efficient detection of Dimethylamine (DMA) and Trimethylamine (TMA) vapors, the two primary amines that are primary bio-indicators for many applications like quality monitoring of freshness of fish, biomarker for couple of diseases like Non-Alcoholic Fatty Liver Disease (NAFLD), renal disorder etc.. Compared to the state-of-the-art, the developed sensor offered three distinct advantages:(i) this is the first report of DMA, TMA detection with FET device employing MoS<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub>-ZnO hybrid channel offering fast response and recovery (ii) the ability to detect the target species at room temperature owing to very high free surface energy associated with the hybrid channel region (iii) improved lowest detection level (0.5 ppm for DMA and 1 ppm for TMA) due to excessively high surface to volume ratio. The underlying mechanistic framework for such superior performance was primarily attributed to the judicious choice of the channel material coupled with device architecture. Formation of the p-n junction (p-MoS<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> and n-ZnO) in the channel region and the associated charge separation assisted field generation therein leads to easy dissociation of target vapor species (low operating temperature, improved lowest detection level), while the majority carrier-driven fast charge transport in the channel region causes fast response and recovery in such FET device.