摘要
目的太阳能选择性吸收涂层是太阳能热利用的核心材料。方法采用磁控溅射法制备Ti N/TiNO/SiO_(2)太阳能选择性吸收涂层,测定红外反射层Ti N、吸收层Ti NO的折射率n、消光系数k,对Ti N层建立Tauc-Lorentz模型进行数据迭代优化拟合,对Ti NO层建立Drude模型进行数据迭代优化拟合。通过TFCalc光学镀膜设计软件,设置连续目标在300~1500 nm光谱区反射率低于5%,得到软件优化的反射率曲线、各层的最优厚度,确定优化的工艺参数。利用UV-VIS-NIR、FTIR、SEM、XRD、EDS、AFM和XPS表征优化涂层的光学性能、评价热稳定性。结果优化后的涂层,吸收率为0.906、发射率为0.0852;经265℃、600 h热处理后,涂层的吸收率和发射率分别为0.933和0.1033,PC值小于0.01。随热处理时间的增长,α有小幅上升;热处理时间对ε的影响较小;这与表面Si O_(2)氧化物薄膜层在一定程度上阻止了晶粒的长大有关。热处理后,发现涂层表面局部位置有少量的小坑,但涂层的表面成分不变。非晶基质Si O_(2)和Ti O_(2)的再结晶是吸收率提高的主要原因;热处理后的涂层表面非常致密,粗糙度的降低有利于阻碍氧原子向内层的扩散,可以有效提高涂层的热稳定性。结论优化的Ti N/TiNO/SiO_(2)涂层,选择性吸收性能及热稳定性得到有效提高,具有较好的实际应用前景。
Solar selective absorption coating is the core material of solar thermal utilization.A TiN/TiNO/SiO_(2) solar selective absorption coating was deposited by magnetron sputtering.The refractive index(n)and extinction coefficient(k)of infrared reflector layer TiN and absorption layer TiNO were determined,while the optical constants of anti-reflector layer SiO_(2) were reported in the literature.The ellipsometer angle(Ψ,Δ)was measured by ellipsometer and studied by W-VASE analysis and fitting software.The Tauc-Lorentz model in terms of infrared reflector layer TiN was established for data iteration and optimization and fitting,and the Drude model in terms of absorption layer TiNO was established for data iteration and optimization and fitting.The refractive index decreased from the infrared reflector to the anti-reflector,and the gradient structure reduced the surface reflection,which conformed to the design of optical interference coating.Optimization parameters in which continuous target reflectance was lower than 5%in the range of 300-1500 nm were set by TFCalc software.The reflectance curve optimized by the software and the optimal thickness of each layer were obtained,and the optimized process parameters were determined.The reflectance curve optimized by the software and the reflectance curve of prepared coating were basically consistent in the wavelength range of 400-1500 nm,and the experimental curve increased rapidly in the wavelength range of 1500-2500 nm.The optical properties and thermal stability of the coating were optimized by UV-VIS-NIR,FTIR,SEM,EDS,XRD and XPS.The absorptivity and emissivity of the optimized coating were 0.906 and 0.0852 respectively,which were consistent with the optimized results.After heat treatment at 265℃for 600 h,the absorptivity and emissivity of the coating were 0.933 and 0.1033,respectively,and the PC value was less than 0.01.The surface composition of the coating did not change before and after heat treatment.The content of oxygen element increased slightly,indicating that the coating was not oxidized,showing a good oxidation resistance.No defects such as grain boundaries and cracks were observed,which was conducive to preventing the diffusion of oxygen atoms to the internal coating.There was a small increase about absorptivity with the increase of heat treatment time,while there was not a similar pattern about emissivity.This was related to the fact that the surface SiO_(2) oxide film layer prevented the grain growth to a certain extent.After heat treatment,a small number of pits were found locally on the surface of the coating,but the surface composition of the coating was almost unchanged.Further analysis showed that the recrystallization of SiO_(2) and TiO_(2) in amorphous matrix was the main reason for the improvement of absorptivity,and the elimination of residual stress during crystallization also contributed to the improvement of absorption efficiency.The surface of the coating after heat treatment is very dense,and the reduction of roughness is conducive to preventing the diffusion of oxygen atoms to the inner layer,which can effectively improve the thermal stability of the coating.The selective absorption performance and thermal stability of the optimized TiN/TiNO/SiO_(2) coating have been effectively improved,which is conducive to a strong practical application prospect.
作者
严梦迪
邓敏蒂
陈金志
袁文旭
刘瀚泽
谢浩
闵捷
YAN Mengdi;DENG Mindi;CHEN Jinzhi;YUAN Wenxu;LIU Hanze;XIE Hao;MIN Jie(School of Materials and Chemical Engineering,Hubei University of Technology,Wuhan 430068,China;School of Industrial Design,Hubei University of Technology,Wuhan 430068,China;Hubei Engineering Technology Research Center of Environmental Purification Materials,Research Institute of Materials Science,Hubei University of Education,Wuhan 430205,China)
出处
《表面技术》
EI
CAS
CSCD
北大核心
2024年第20期190-197,共8页
Surface Technology
基金
国家自然科学基金青年科学基金(52002159)
热能动力技术重点实验室开放基金(TPL2018A03)
湖北省教育厅科学研究计划资助项目(D20223003)
湖北省建设科技项目。
