MULTILAYER SELECTIVE ABSORBING COATING FOR SOLAR COLLECTOR AND METHOD OF MAKING SAID COATING Russian patent published in 2010 - IPC F24J2/48 

FIELD: physics.

SUBSTANCE: multilayer selective absorbing coating is meant for application on the outer surface of the heat receiving panel of a solar collector which converts solar radiation to heat. The coating consists of a first titanium layer with thickness d₁=λ₀/4n₁, a second layer in form of oxides, carbides or nitrides of titanium TiC_xO_y or TiN_x with thickness d₂=λ₀/2n₂, a third layer in form of titanium silicide TiSi with thickness d₃=λ₀/4n₃, where the refraction index of the third layer n₃=(n₂×n₀)1/2, where λ₀ is wavelength which corresponds to the maximum of the solar radiation spectrum, n₀ is refraction index of air, n₁ is refraction index of the first titanium layer, n₂ is refraction index of the second layer made from TiC_xO_y or TiN_x. The coating is made through high vacuum sputtering of a titanium layer, after which reactive sputtering of titanium is carried out in a CO₂ or N₂ atmosphere at pressure (2.5-8)×10^-2 Pa at a rate of not more than 30 P₂, where P₂ is partial pressure of CO₂ or N₂, Pa. Finally, titanium silicide TiSi is reactively sputtered onto the processed surface through reactive sputtering of titanium in the atmosphere of monosilane vapour at pressure (3×10^-1) Pa.

EFFECT: high efficiency of coating, environmental safety and high efficiency of depositing the coating.

2 cl, 1 dwg