Developing electronic sensors for ammonia (NH₃) is very useful for environmental monitoring and diagnostic purposes. In this work, a highly sensitive, organic field-effect transistor (OFET) based, room temperature sensor for NH₃ has been fabricated using dinaphtho [2,3-b:2′,3′-f]thieno [3,2-b]thiophene (DNTT), which showed a fast response to low concentration of the analyte down to 100 ppb. A thin film of solution-processed polymethyl methacrylate (PMMA) has been used as the gate dielectric material and its hydrophobic surface promoted structured growth of organic semiconductor, DNTT, by inducing mass transfer. By controlling the thickness and thereby exploiting the growth dynamics of the semiconductor film, the sensor performance was improved. The sensitivity of the device towards 1 ppm of NH₃ was almost doubled with a thinner and porous film of DNTT as compared to that with a thick film. Morphological studies of the sensing layers, using atomic force microscopy (AFM), have established this structure-property relation. The variations in different transistor parameters have been studied with respect to different analyte concentrations. The p-channel devices in the enhancement mode showed depletion upon exposure to NH₃. The devices exhibited a fast response and good recovery to the initial state within 2 min.

开发用于氨 (NH ₃ ) 的电子传感器对于环境监测和诊断目的非常有用。在这项工作中，一个高度敏感的，有机场效应晶体管（OFET）系，空间NH温度传感器₃已经制造使用二萘并[2,3-B：2'，3'-F]噻吩并[3,2-乙]噻吩 (DNTT)，它对低至 100 ppb 的低浓度分析物显示出快速响应。溶液处理的聚甲基丙烯酸甲酯 (PMMA) 薄膜已被用作栅极介电材料，其疏水表面通过诱导传质促进了有机半导体 DNTT 的结构化生长。通过控制厚度，从而利用半导体薄膜的生长动力学，传感器性能得到改善。设备对 1 ppm NH ₃的灵敏度与使用厚膜相比，使用更薄且多孔的 DNTT 膜几乎翻了一番。使用原子力显微镜 (AFM) 对传感层的形态学研究已经建立了这种结构-性能关系。已经针对不同的分析物浓度研究了不同晶体管参数的变化。增强模式下的 p 沟道器件在暴露于 NH ₃时显示出损耗。该器件表现出快速响应并在 2 分钟内良好地恢复到初始状态。