Studies on gas sensing performance of CuO-modified CdIn2O4 thick film resistors

Cadmium indium oxide powder was derived from calcination of cadmium indium sulphide prepared by a flux method. The material was confirmed by XRD. Thick films of this powder were prepared on glass substrates using screen-printing technique. CuO-modified CdIn2O4 thick films were obtained by dipping technique in which Cu2+ was incorporated as an additive into the CdIn2O4 base material. The films were fired at 500 °C for 2 h. The films were characterized by SEM and EDAX. The electrical conductivity of the films was determined. The gas sensing performance of pure and modified CdIn2O4 films were investigated for various gases. The films showed best response to chlorine gas. Modified films were found to be more sensitive than pure CdIn2O4 to chlorine gas. The quick response (∼6 s) and fast recovery (∼22 s) are the main features of the modified sensor.