Improved Performances of Room Temperature Gas Sensor by Indium Doping of P3HT/ZnO Hybrid Nanocomposites

Hybrid films of poly(3-hexylthiophene) (P3HT)/indium-doped zinc oxide (IZO) and undoped ZnO were developed in this work for the detection of volatile organic compounds at room temperature. Indium-doped and undoped ZnO nanoparticles were synthesized using the sol–gel method and mixed with P3HT before deposition using the spin-coating technique on interdigitated electrodes to form the hybrid sensing layers. The obtained films were characterized by X-ray diffraction, scanning electron microscopy, and atomic force microscopy, confirming the presence of P3HT/ZnO hybrid phase and well-dispersed particle structures with nanometric size in the composite thin films. The sensing properties of the sensors were studied for the reduction of gas (ethanol) at room temperature. In particular, the composite P3HT/IZO1% exhibits a maximum response of 104% and a fast response time of about 58 s to 3000 ppm of ethanol concentration at room temperature.