Investigation of ZnO thin-film sensing properties for CO۲ detection: effect of Mn doping

AbstractA simple spray pyrolysis technique has been used to fabricate ZnO/Mn thin films with different Mn concentrations (۰, ۵, ۱۰ and ۱۵ mol.%) for gas sensing applications. X-ray diffraction (with Cu-Kα radiation) patterns of the samples revealed the formation of single-phase wurtzite structure. The samples were characterized using field-emission scanning electron microscopy and scanning tunneling microscopy. The investigation revealed that the surface of pure ZnO thin film appears rougher and containing bigger grains. The response of the pure and Mn-doped ZnO thin-film gas sensors was checked at different temperatures ranging from ۱۲۰ up to ۲۰۰ °C, to investigate the optimum sensing efficiency. The gas sensing results have demonstrated that the pure ZnO thin film exhibited higher sensitivity to CO۲ gas at ۱۵۰ °C operating temperature, while the sensitivity reduced with the increase in gas pressure. Although the sensitivity of doped samples was lower than the pure sample, the sensitivity increased with the increase in pressure.

کلیدواژه ها:

ZnO/Mn ، Sensing properties ، CO gas ، Thin films