formulation and characterization of cr2o3 doped zno thick films as h2s gas sensor

Cr2O3 doped ZnO thick films have been prepared by screen printing technique and firing process. These films were characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM), and EDX. H2S gas sensing properties of these films were investigated at different operating temperatures and different H2S concentrations. The 7 wt. % Cr2O3 doped ZnO thick films exhibits excellent H2S gas sensing properties with maximum sensitivity of 99.12 % at 300 oC in air atmosphere with fast response and recovery time.