Dependence of sensitivity and reproducibility of CdS oxygen sensors

The electrical conductance of the CdS-based sensors increased or decreased when exposed to CO or SO2 gases, depending on the operation temperature and stoichiometric composition of the film. A correlation between the IR spectrum and inversion of the chemisorbed complex charge state was observed. This is considered to be a favourable basis for the detection of atmospheric pollutants in ambient air, by combination of two sensor systems.