Development of nanostructured CdS sensor for H2S recognition: Structural and physical characterisations

Abstract

In this article, the gas-sensing properties of novel gas sensors operating at room temperature based on nanostructured cadmium sulphide (CdS) were investigated. The sensors exhibited high response (13%) to H2S at an operating temperature of 100°C. The X-ray diffraction measurements confirmed that the films grown by this technique have good crystalline hexagonal structure. The surface morphology (SEM) of the CdS film showed that the nanoparticles are fine with 40-50 nm average particle size. Optical studies revealed a high absorption coefficient (104cm-1) with a direct gap of 2.54 eV. The films show n-type conduction mechanism with room temperature dc electrical conductivity 10-6 (Ω cm)-1. The activation energies of an electrical conduction have been determined and the possible conduction mechanism is discussed. © 2013 Copyright Taylor and Francis Group, LLC.