H₂S detection using low-cost SnO₂ nano-particle Bi-layer OFETs

Abstract

In this article, a unique platform with an Organic Field-effect Transistor (OFET) integrated with metal oxide nanoparticles for sensing of H₂S gas is presented. Metal oxide nanoparticles such as SnO₂ and ZnO synthesized using herbal techniques were used in the fabrication of OFETs using a bi-layer technique. The as-synthesized nanoparticles were characterized by Field Effect Scanning Electron Microscopy (FE-SEM), X-ray Diffraction (XRD) and UV–vis Spectroscopy (UV–vis) to establish the material properties. We showed that the SnO₂ based OFETs displayed better response for H₂S at room temperature (25°C) compared to the OFETs fabricated with ZnO. The characterization of the sensors by using extracted electrical parameters like field-effect mobility (μ), On-Current (I_on), threshold voltage (V_T) and saturation current (I_Dsat) establish the fact that the SnO₂ based OFETs detect H₂S gas at room temperature. Plausible mechanisms explaining the H₂S gas detection by bi-layer film were discussed. On the other hand, the sensitivity of these OFETs against other reducing gases was less.