新型太阳光谱选择性吸收涂层的热稳定性

STUDY ON THERMAL STABILITY OF SOLAR SELECTIVE ABSORBING SURFACES WITH NEW MATERIAL

利用铝合金靶 (LY13) 在氩气和空气气氛中进行直流反应溅射 ,可以得到渐变型或干涉型太阳光谱选择性吸收涂层。当氩气与空气之比大于 0 14～ 0 16时得到由AlxOy 和AlNx 组成的纯介质膜 (AlxOy AlNx)其折射率 (n)和消光系数 (k)分别为 1 6 5～ 1 88和 0 0 0 2～ 0 .0 0 5。将AlxOy AlNx 膜和纯AlN膜作为减反射膜分别沉积在具有相同吸收层的样品上 ,在真空压强 4 5× 10 3 Pa,4 0 0℃下烘烤 30min ,AlxOy AlNx 比AlN更稳定。在高硼硅玻璃和抛光不锈钢上 ,沉积了厚度约为 2 5 0nm的吸收涂层 (AlxOy AlNx Al)和 6 0nm厚的减反射层 (AlxOy AlNx)构成太阳光谱选择性表面。真空中 4 0 0℃、5 0 0℃、6 0 0℃ ,烘烤 30min后 ,其α/ε反而由 11 4升高至 14 4 6 ;5 5 0℃烘烤4 0h与 4 5 0℃烘烤 10h相比仅仅发射率稍微有点升高 ,其吸收比不变。试样在空气中 35 0℃烘烤 10h与真空中4 5 0℃烘烤 10h的结果相当接近 ,它们的α/ε分别是 13 0和 13 2 9。

The d.c. reactive sputtering with aluminum alloy(LY13)in air and argon was taken,the solar selective absorbing surfaces with the graded and the multilayer structure was obtained.When the ratio of the flux of air and argon was above 0.14～0.16,the coating(Al x O y AlN x )consisting of Al x O y and AlN x was got whose index of refraction and extinction coefficient were 1.65～1.88 and 0.002～0.008 respectively,The Al x O y AlN x and AlN anti reflection coatings with proper thickness were deposi ted on the same absorbing coatings,after heating at 450℃ for 30 minutes in 4.5×10 -3 Pa vacuum,Al x O y AlN x coatings had higher stability than AlN.The Al x O y AlN x anti reflection coatings with thickness 60nm and about 250nm Al x O y AlN x Al absorbing coatings was deposited on the boron silicon glass and stainless steel respectively to get solar selective absorbing surfaces.In vacuum heating at 400℃,500℃,600℃ respectively for 30 minutes,their α/ε increased from 11.4 to 14.6.The emittance of the specimen heated 550℃ at for 40 hours was a little higher than that of heated 450℃ at for 10 hours,and their absorptance were equal.The specimen was heated at 350℃and 450℃ for 10 hours respectively,and the result was similar.The α/ε of them were 13.0 and 13.29 respectively.