Hybrid of P3HT and ZnO@GO nanostructured particles for increased NO2 sensing response

The NO2 sensing properties and operational mechanism of the hybrid formed from poly(3-hexylthiophene) (P3HT) and zinc oxide-graphene oxide (ZnO@GO) nanoparticles were investigated. We prepared graphene oxide (GO) and zinc oxide (ZnO) core-shell nanostructured particles with ionic aggregation. Gas sensors were fabricated by spin coating a mixture of P3HT with ZnO@GO on oxide-coated silicon wafers leading to formation of organic field-effect transistors (OFETs). The NO2 sensing properties of the obtained devices were investigated at room temperature. By means of observing conductance changes before and after exposure to NO2, it was demonstrated that the hybrid of P3HT with 60 wt% ZnO@GO composites exhibits 210% sensing response to 5 ppm NO2 gas exposure for 5 min at room temperature. The sensing mechanism included a contribution from the hybrid that was not observed from pure P3HT or by adding either ZnO or GO alone.