Hydrogen Sulfide Sensing Properties of CuXS-In Heterojunctions

In this paper, a study on the development of indium-doped CuxS heterojunction-based conductometry sensors is presented. To fabricate the sensors, thick films of In-CuxS heterojunctions were sprayed directly on the alumina sensing platform provided with interdigitated Pt electrodes. The effect of the doping level with different nominal amounts of InCl3 additive (0%, 3%, and 5%) on the structural, morphological and optical properties of CuxS films was first studied by XRD, AFM, UV-Vis and Raman spectroscopy. Moreover, the electrical and sensing characteristics towards low concentrations of hydrogen sulfide (H2S) in air were investigated. The tests carried out clearly demonstrated the positive effect of In doping on the H2S sensing performance of CuxS. The 5%-doped CuxS sensor showed the highest sensitivity to the target gas compared to the other sensor, as well as good stability and selectivity properties.