Optimization of ZnS/Ag/ZnS Multilayer Thin Film Systems for Heat Mirror Applications

A multilayer system of dielectric/metal/dielectric (D/M/D) thin films on glass substrate for energy-efficient heat mirror applications were designed theoretically and fabricated experimentally to optimize the performance. The thickness of an Ag film sandwiched between two ZnS layers of specific thickness was considered as the design parameter using IMD-Software. The measured spectral transmittance and reflectance are compared with those computing using relevant software. A good agreement between the theoretical and experimental spectra was obtained. The system performance is optimized by numerical calculations of layers thicknesses then verified experimentally and g/D/M/D device was fabricated. Maximum performance was achieved with Ag thickness in the range of 10 -15 nm and thickness of 15 nm for each ZnS layer.