Complex (As2S3)(100−x)(AgI)x chalcogenide glasses for gas sensors

The sorption properties of thin amorphous As–S–AgI layers were investigated using resonating cantilevers. The coatings were deposited on the cantilevers by vacuum thermal evaporation from the corresponding bulk glasses, followed by exposure to analytes (water, volatile organic compounds, ammonia) with different concentrations. The highest sensitivity was observed towards acetone, the analyte with one of the highest molecular weights and with the lowest dipole moment among the tested analytes. The sensor acted primarily as a microbalance distinguishing the vapors by the difference in their molecular weight. However, the peculiarities in the interaction sensing coating–analyte molecules are reflected in the sensitivity towards molecules with different polarities. The short response and recovery times together with the linear increase of the response signals with the analyte concentration make the investigated As–S–Ag films a promising candidate for gas sensitive elements.