Design And Optimization Of Mo-AIN Solar Spectrally Selective Absorbing Coating

Selective absorbing coating is a kind of functional material which converts solar energy into heat. Because its working life is shorter in the utilization of solar energy under the low temperature, and unstable under the environment of high temperature, in recent years,researchers and scientists have began to widely pay attention to the technology of the most promising solar thermal power generation. To promote the development of the technology,need to develop selective absorbing coating which is suitable for the high temperature conditions and improve its absorption performance. These researchs have important academic meaning and application value on the engineering for improving the efficiency of solar thermal power generation and decreasing the generating cost.Mo-AlN is selected as absorbing coating, AlN as anti-reflection and metal Mo for infrared reflector. The volume fraction of metal Mo in the selective absorbing layers, and the thickness of absorbing coatings with anti-reflection need to be optimized by using Mathematical software. Results show that the volume fraction of Mo in the absorbing coatings determines metallicity of the absorbing layers, as well as also has a direct influence to the selective absorption performance for the whole film system. The thickness of high metal volume fraction absorbing layer has larger effect on the membrane system relative to low metal volume fraction absorbing coating. When optimum volume fraction of Mo is0.2/0.8, the optimal thickness of 90nm/50 nm, absorptivity is α = 0.803, emissivity ε=0.011.Combined with the optimal thickness of anti-reflection of 44.09 nm, absorptivity α=0.923,emissivity ε=0.012(100 ℃).