The sensing properties of carbon monooxide were investigated as a function of mixing ratio and the lamination structure of 3mol% ZnO-doped SnO2 and 3mol% SnO2-doped ZnO. The lamination structures were fabricared monolayer, double layer, and hetero lay...
The sensing properties of carbon monooxide were investigated as a function of mixing ratio and the lamination structure of 3mol% ZnO-doped SnO2 and 3mol% SnO2-doped ZnO. The lamination structures were fabricared monolayer, double layer, and hetero layer of SnO2, ZnO, and theirs mixture composition using thick film process. There was no second phase by the reaction of SnO2 and ZnO. The conductance was decreased by the addition of ZnO in SnO2, but it was increased with the addition of SnO2 in ZnO. The conductance was increased with temperature and the inlet of CO. There was no improvement of sensitivity in the structure of mono- and double-layer. The hetero-layer structure, however, of SnO2·3ZnO-ZnO·3SnO2 showed the higher resistivity and the highest sensitivity. Ohmic characteristics was confirmed by the linear properties for I-V measurements.