Snox/Ag/Snox Heat-Reflector Coatings Prepared By Dc Sputtering

Transparent heat reflectors have been prepared by DC sputtering of pure metal targets on glass substrates at room temperature. These are three-layer coatings based on a high reflective silver film surrounded by transparent tin oxide layers, which reduce greatly the silver reflection in the visible range, but not in the infrared region. In fact, such infrared reflectance has been controlled by the Ag interlayer thickness. Besides, during the tin oxide growth by reactive deposition, both the oxygen partial pressure and the sputtering time have been tuned to maximize the visible transmission while avoiding the possible Ag oxidation. In this way, optimized SnOx/Ag/SnOx coatings have been achieved with high luminous transmittance (tau(L) = 81% including the glass substrate) and low solar heat gain (g = 0.55), as required for energy-efficient glazing applications.