Fabrication and Optical Properties of Low-Emissivity Coatings of AlSiN and AgCuNd-Alloy Multilayer Films on Glass

Abstract

Transparent low-emissivity coatings comprised of AlSiN and Ag-alloy multilayer films were investigated. All films were prepared by dc magnetron sputtering. AlSiN/Ag-alloy/AlSiN/Ag-alloy/AlSiN multilayer films were prepared on glass substrates. Three types of Ag-alloys were used: Ag87.5Cu12.5, Ag88Au4.6Cu7.3Ti0.1, and Ag95.8Cu2.2Nd2 films. Thicknesses of the Ag-alloy films were controlled to be in the range of 10–12 nm thick. Compared to the AgCu- and AgAuCuTi-alloys, the AgCuNd-alloy films showed superior optical properties. The maximum transmittance (Tmax) was 85.6% for multilayer coatings with 10-nm-thick Ag95.8Cu2.2Nd2-alloy films. The maximum transmittance is 4 and 7% higher than for the coatings with Ag89.5Au7Cu3Ti0.5- and Ag87.5Cu12.5-alloy films, respectively. In the case of AlSiN (43 nm)/Ag95.8Cu2.2Nd2 (11 nm)/AlSiN (86 nm)/Ag95.8Cu2.2Nd2 (11 nm)/AlSiN (43 nm) multilayer coatings, 79.7% visible light transmission (Tvis) and a shading coefficient of 0.50 were obtained. This indicates that well-balanced transparent low-emissivity coatings with both high visible transparency and good solar infrared shading can be produced for multilayer coatings with the AgCuNd-alloy films.