MoO2-NiO-Al2O3太阳能选择性吸收涂层的制备及其光学性能研究

Synthesis and Optical Performance of MoO_2-NiO-Al_2O_3 Solar Selective Absorbing Coating

以氯化钼和氯化镍、氯化铝、无水乙醇和乙二醇为主要原料,采用溶胶凝胶法结合旋涂工艺,在石英基片上制备了MoO2-NiO-Al2O3多层渐变太阳能选择性吸收涂层,通过扫描电子显微镜观察了涂层的断面形貌并测量出了涂层厚度,通过紫外可见光分光光度计、傅里叶红外光谱仪等仪器对涂层光学性能进行了分析表征。结果表明:当高、中、低掺杂层的填充因子分别为0.95,0.43,0.18,高掺杂、中掺杂、低掺杂、减反射层各层的溶胶体积分别为0.2,0.18,0.22,0.08ml时,MoO2-NiO-Al2O3涂层的光吸收性能最佳,吸收率为90%。并通过研究发现,在紫外-可见-近红外光范围内,填充因子对复合涂层光吸收性能的影响随太阳光波段的不同而不同,并且随着缺少了的掺杂层的填充因子的增大,反射光谱第一个干涉极小值点蓝移,随着缺少了的掺杂层的填充因子的减小,干涉峰变平坦甚至消失。

The MoO2-Ni O-Al2O3 multilayered solar selective absorbing coatings were deposited in sol-gel method on quartz substrate. The influence of the coating conditions,including the MoO2mole-fraction,number of absorbing layer and thickness,on reflectance and transmittance of the coatings were investigated with scanning electronic microscopy,ultraviolet visible near-infrared spectroscopy,and Fourier transform infrared spectroscopy. The results show that the growth conditions strongly affect the optical behavior of the MoO2-Ni O-Al2O3 coatings. Under the optimized conditions： 0. 08 ml thick anti-reflection layer,MoO2 mole-fractions of 95%,0. 43%,and 18% with thicknesses of 0. 20,0. 18,and 0. 22 ml in the high-,medium- and low-doped layers,respectively,the coating has the highest absorptance of 90%. In 200 - 2500 nm range,the impact of MoO2 mole-fraction on absorption depends on ＂colors of sunlight＂to a varying degree. For the coatings with no MoO2 in the doped-layer,an increase of MoO2 mole-fraction resulted in a blue-shift of the 1st interference valley; but a decrease of MoO2mole-fraction weakened the interference. Tab. 1 deposition conditions of the MoO2-Ni O-Al2O3 coatings