Au-(Y2O3)X(ZrO2)1-X Thin Films as an All-Optical Method for Measuring Emissions at High Temperatures

Gold nanoparticle embedded yttria stabilized zirconia (Au-YSZ) thin films have been deposited on optically transparent sapphire substrates. Absorbance due to the Au nanoparticle surface plasmon resonance (SPR) band was monitored as concentrations of various gases, such as O₂, H₂, NO₂, and CO in N₂, were varied and flowed over Au-YSZ films at elevated temperatures (~500degC). Detectable changes in the SPR band were observed for all gases, with the detection limit for NO₂ being 5 ppm. In addition, Au-YSZ films have repeatedly shown stable sensing over 48 hour periods at 500degC during O₂ and H₂ titration experiments. This all-optical approach for the detection of gases at high temperatures is preferred over electrical measurements due to the simplicity of the device design and the absence of conductive contacts.