Parameter optimization of the OTFT gas sensor and its trace NO_2-sensing properties

摘要

In this paper, the gas-sensing characteristics of gas sensors for Organic Thin-Film Transistors (OTFTs) with the different ratio of the channel length to width and thickness of the insulating layer were studied. The results showed that the device parameters had the influence on the sensitivity and response time of sensors, and the optimized parameters of OTFT sensors were obtained, that was, the ratio of the channel length to width was between 160 and 640, and the insulating layer was 195 nm in thickness. The OTFT sensor with the a-Sexithiophene (a-6T) film incorporated into a sensitive layer was observed to respond strongly to the trace nitrogen dioxide (NO_2) vapor ranging from 0.2 to 1 ppm at room temperature.