Enhanced ethanol sensing response of nanostructured Ce-doped CuO thin films

• Published in: Materials chemistry and physics 2022-03, Vol.280, p.125841, Article 125841
• Main Authors: Bosigo, Romang, Lepodise, Lucia M., Chimowa, George, Muiva, Cosmas
• Format: Article
• Language: English
• Subjects: Ammonia; Atomic force microscopy; Ce doping; Cerium; CuO; Doping; Ethanol; Ethanol sensing; Gas sensors; Spray pyrolysis; Thin films; VOCs; Volatile organic compounds
• ISSN: 0254-0584; 1879-3312
• DOI: 10.1016/j.matchemphys.2022.125841

CuO based thin films doped with Ce concentrations varying from 0 to 8 mol% were prepared by chemical spray pyrolysis. X-ray diffraction analysis revealed bandgap modulation which is dependant on Ce doping and also showed perservation of the single phased monoclinic CuO structure for all the films after doping indicating successful substitution of Ce4+ ions in host matrix. SEM and AFM microscopy showed changes in morphology as Ce doping was increased. And this appeared to have a significant role on the ethanol sensing capabilities of the thin films which were measured at different working temperatures. Good gas sensing stability and maximum response was observed for the 4% Ce thin film. The sensing device was found to be more responsive towards ethanol than other common volatile organic compounds such as methanol, acentronile, ammonia and acetone. The response and recovery times for the sensing suggest a chemosorbption mechanism. •Ce-doped CuO thin films were synthesized by simple chemical spray pyrolysis route.•Ce doping has an influence in the CuO sensing performance.•Sensitivity at relatively low temperatures achieved.•The sensing mechanism was ascribed to the oxygen vacancies induced by dopant.