Energy-saving spectrally-selective coatings based on MoO3/Ag thin films

• Transparent heat mirrors transmit light and reflect infrared heat.
• In this work, they were deposited using MoO3/Ag multilayer coatings.
• The MoO3 films were smooth, had high refractive index, and wide bandgap.
• The fabricated heat mirrors had high visible transparency and infrared reflection.

Transparent heat mirrors are spectrally selective coatings that transmit light and reflect heat in the form of infrared radiation. In this work, these coatings were achieved by depositing a two-layer structure consisting of molybdenum oxide thin films deposited on silver thin films by thermal evaporation. First, the structural, chemical, and optical properties of molybdenum oxide thin films, that are relevant to their use in transparent heat mirrors, were investigated. Then, the optical properties of the two-layer structure were determined. Moreover, chemical depth profiling was carried out to investigate the spatial distribution of the elements among the layers. The deposited heat mirrors were found to exhibit the desired behavior of high visible transparency and high infrared reflection.

Transparent heat mirrors are multilayer structures that transmit light and reflect infrared radiation, thus conserving energy. In this work, this was achieved by deposition of molybdenum oxide thin films on top of silver layers. The silver layer provides the desired high infrared reflectance. The MoO3 thin film is a dielectric material characterized by wide band gap and high refractive index. It works as an antireflective layer, and thus provides the necessary high visible transparency.Figure optionsDownload as PowerPoint slide