Advanced solar selective coatings
Advanced solar selective coatings employ two patent technologies :
(1) double cermet film structure with the highest photothermal efficiency
(2) metal-Aluminum nitride cermet (M-AlN) materials deposited by a novel sputtering technology.
The typical film structure of M-AlN cermet selective surfaces

schematically shown in the figure one

Models	孜47℅150	孜58℅180	孜58℅192	孜58℅210
Weight	1.35㊣0.12kg	2.29㊣0.18kg	2.45㊣0.20kg	2.67㊣0.22kg
Structure	All glass coaxial double-layer tubes	All glass coaxial double-layer tubes	All glass coaxial double-layer tubes	All glass coaxial double-layer tubes
Outer tube diameter	孜47㊣0.7mm	孜58㊣0.7mm	孜58㊣0.7mm	孜58㊣0.7mm
Inner tube diameter	孜37㊣0.7mm	孜47㊣0.7mm	孜47㊣0.7mm	孜47㊣0.7mm
Outer Tube thickness	1.6㊣0.15mm	1.8㊣0.15mm	1.8㊣0.15mm	1.8㊣0.15mm
Inner tube thickness	1.6㊣0.15mm	1.6㊣0.15mm	1.6㊣0.15mm	1.6㊣0.15mm
Tubes length	1542㊣4mm	1812㊣4mm	1932㊣4mm	2100㊣4mm
Material of coating	AlN/AIN-SS/Cu	AlN/AIN-SS/CU	AlN/AIN-SS/CU	AlN/AIN-SS/CU
Absorptance	0.94~0.96	0.94~0.96	0.94~0.96	0.94~0.96
Emittance	0.04~0.06	0.04~0.06	0.04~0.06	0.04~0.06
Vacuum	P≒5℅10-3pa	P≒5℅10-3pa	P≒5℅10-3pa	P≒5℅10-3pa
Transmittance of Outer Tube	0.91	0.91	0.91	0.91
Stagnation temperature (height)	270~300⊥	270~300⊥	270~300⊥	270~300⊥
Heat-loss coefficient	≒0.6w/ m2*⊥)	≒0.6 w/ (m2*⊥)	≒0.6 w/ (m2*⊥)	≒0.6 w/ (m2*⊥)
Bearing hailstone ability	hailstone diameter孜25mm	hailstone diameter孜25mm	hailstone diameter孜25mm	hailstone diameter孜25mm
Pressure-endure ability	1MPa	1MPa	1MPa	1MPa