The influence of preparation conditions on the optical properties of titanium nitride based solar control films

Single layers of TiO2 and TiN films, as well as triple layer structures of TiO2/TiN/TiO2, have been sputtered on substrates at temperatures ranging from room temperature to 450 °C. A new combination of materials was used to make the substrate heater. X‐ray diffraction (XRD) was used to study the infiuence of substrate temperature upon the grain size. The optical constants n and k for TiO2 were evaluated. The oxide films grown at a higher deposition rate and on 300 °C substrates had a refractive index of 2.48 at 550 nm, compared to 2.29 for the film grown at a lower rate and at room temperature. A single layer of TiN exhibits improved optical selectivity with increased substrate temperature up to 300 °C. Further increase of the substrate temperature only caused a small effect on the heat mirror properties of the film. The triple layer is improved with increased substrate temperature. However, at temperatures of 300 °C and higher, a reduction of the heat mirror performance occurs and it is demonstrated by o...