High Detectivity Ammonia Gas Sensor of Pentacene Based Organic Material with OXIDE MESH

Abstract

Ammonia gas sensing properties of pentacene based organic gas sensor fabricated by thermal evaporation method on amorphous oxide semiconductor (a-SiInZnO) mesh. The amorphous oxide semiconductor mesh layer was fabricated by RF sputtering and conventional photolithography. Insertion of a dense mesh layer has been found to significantly improve gas sensing properties. In the case of a conventional pentacene thin film, the SEM image analysis resulted in a uniform surface. This means that ammonia gas cannot be adsorbed well on the surface. The insertion of the mesh layer improves the surface volume ratio of the organic thin film and induces more ammonia gas to be adsorbed on the pentacene surface. As a result, it was confirmed that even when the ammonia gas concentration was 5 ppm or less, the detection rate was higher than that of a conventional pentacene thin film. It is expected to be applied to various high-sensitivity organic-based gas sensors.