Research On The Gradient-index Broadband Antireflection Performance Of Solar Glass

Within the widely application of the solar photovoltaic and thermal components, improving solar glass transmittance is becoming a hot spot of research all over the world. In order to reduce costs and improve efficiency, reflective film on the glass coating system is the most effective method. Solar energy application needs to have good antireflection performance in the wide band.Among various kinds of antireflection technology, antireflection gradient-index due to getting broadband, nearly zero reflection characteristics has become a research focus in the field of antireflection. As the application of gradient-index antireflection and related theoretical study is very few, many basic problems are still not clear whitch affects the further development of gradient-index antireflection technology.TFCalc and Macleod optical thin film design softwares are applied in this article, research, calculated the straight Line, conic curve Conic and the symmetrical conic curve Aconic, cosine curve Cos and the symmetrical cosine curve Acos, five kinds of gradient-index distribution curve in membrane layers for5～300and layer thickness of physics100,200,300nm, different gradient-index distribution curves, the thickness of the coating layers and affect the performance of gradient-index antireflection film. After calculating of three kinds of film thickness and five kinds of gradient-index distribution form, when the layer number is less than100the transmittance of numerical and through curve shape change; when the layer number is more than100, transmittance and transmittance curve shape have almost no change, the transmittance accuracy can reach delta T<0.02%.For calculation of the three types of film thickness and five kinds of refractive index distribution form, Conic, Aconic and Cos of three kinds of distribution in the form of transmittance and reflectance under different film thickness changes in trends have similar laws; the Line in a larger film thickness in the visible cases have slight fluctuations; this distribution form in visible band has a better antireflection performance; the transmittance and reflectance of Acos under different film thickness have the largest variation, but under the three types of film thickness, the maximum transmittance value, the minimum transmittance infrared wavelengths and the highest reflectance infrared wavelengths have best values.For symmetrical distribution curve form Conic and Aconic in visible range, Aconic antireflection performance is better, at infrared wavelengths, both antireflection performance are equal; symmetrical distribution curve form Cos and Acos in visible range, Cos antireflection performance is better, at infrared wavelengths, Acos antireflection performance is better.Comprehensive analysis shows that the Line and Acos refractive index distribution in the form of broadband antireflection performance are good and also suitable for the application of broadband antireflection.