TFT-CN/P3HT blending active layer based two-component organic field-effect transistor for improved H2S gas detection

To prepare OFET-based sensors by low-cost solution method and improve the sensing ability of polymer OFETs to hydrogen sulfide (H2S), a n-type small molecule dicyanomethylene-terminated quinoid compound (TFT-CN) was blended with P3HT and used as the semiconductor active layer. The introducing of TFT-CN into two-component OFET based sensors greatly improves the sensitivity and selectivity for H2S gas and reduces the limit of detection to 10 ppb level due to the strong binding energy between TFT-CN and H2S. The blending ratio has a great influence on the sensing performance and the sensors show the highest sensitivity for various concentrations of H2S when the ratio of TFT-CN: P3HT is 1: 6 in weight, and the sensitivity can be increased five times than that of the pure P3HT-based sensors. This work proves that it is a simple, effective and low-cost solution method to improve the sensing performance of OFET-based sensors by introducing a functional molecule into conventional polymers which will inspire the performance improvement and application expansion of many traditional materials.