A solar-selective surface with an excellent heat-resistance and optical quality has been developed from zirconium/ zirconium carbide stack. The surface film has been prepared by reactive rf-sputtering of pure Zr target in a gas mixture of methane and argon.
The composition of the optically optimized film is about 6/1 in atomic ratio of C/Zr, which was determined to be a mixture of ZrC and carbon by ESCA. Solar absorptance and infrared reflectance of the surface are 90 and 95%, respectively. The optical property of the surface was stable up to 800°C.
The solar absorptance of the carbon selective-surface can be increased by several percent when a thin oxide layer is overcoated.
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