借助计算机模拟剖析了Ni体积分数对Ni-A12O3太阳光谱选择性吸收薄膜光学性能的影响规律,并依据这一规律指导了以水溶胶一凝胶法制备的Ni-A12O3太阳光谱选择性吸收膜系的优化。模拟结果表明,以呈现类金属特征的基层Ni-A12O3薄膜与Ni体积分数不超过基层0.5倍且呈非金属特征的中间层薄膜组合,在其上再沉积一减反射顶层,如此3层复合可获得高吸收率和低发射率的太阳光谱选择性吸收膜系。依据这一规律指导的以水溶胶一凝胶法制备的Ni-A12O3膜系其吸收率高达0.93,发射率低至0.04,成为一个很好的太阳光选择性吸收表面。
The effect of the volume fraction of nickel on the optical properties of Ni-Alz 03 solar selective absorb- ing films was investigated by computer simulation. The knowledge obtained was used to guide the optimization of Ni-A12O3 coatings fabricated by aqueous sol-gel method. The results of theoretical simulation showed that the double absorbing coatings, of which consists of a base layer with metal-like character and a middle layer with volume fraction less than 0.5 times of the base layer, together with an anti-reflection top layer could pro- duce excellent optical absorption. Based on the principles, the optimized Ni-Al2O3 coatings were fabricated by aqueous sol-gel method, which attained a high solar absorptance of 0.94 and a low thermal emittance of 0.04.