Room-temperature isopropanol sensor via In/Mg co-doped P3HT-ZnO nanocomposite with enhanced selectivity

A novel room-temperature gas sensor based on nanocomposite poly (3-hexylthiophene) (P3HT)/ (In, Mg) co-doped ZnO as an active layer is developed for room-temperature isopropanol detection application. The (In, Mg) co-doped ZnO nanoparticles were synthesised by the sol-gel method and dispersed in the P3HT matrix before spin-coating on interdigitated electrodes to form the sensing layer. Thin films are characterised by X-ray diffraction, high crystallinity of (In, Mg) co-doped ZnO, and a crystalline size of 27–45 nmwas found.The X-ray photoelectron spectroscope (XPS) analysis reveals the incorporation of indium and magnesium into the ZnO lattice. The UV–visible spectroscopy showed high absorption in the UV and visible regions, corresponding to ZnO and P3HT maximum absorption. The sensors were tested on isopropanol at room temperature. It was found that sensors poly (3-hexylthiophene)/(In,Mg) co-doped ZnO exhibit the best sensing performance. A particular result corresponding to the enhancement of sensing performance was illustrated. The synergy effect of each doping element can be observed in the co-doped samples. Indeed, the indium improves the sensitivity of the composite thin films. At the same time, magnesium reduces the response times.