Study On New Antireflective Structure Of Solar Cell Based On Sub-wavelength Grating

The huge application potential of sub-wavelength grating has been attracted great research enthusiasm since it was found. At present, the sub-wavelength grating can be used in several of optical elements, such as polarization devices, the narrowband filter, and the phase plates. Meanwhile the application in anti-reflective coatings is developing into an important topic in recent years. In this paper, two kinds of multilayer sub-wavelength grating anti-reflective layer structures were designed to reduce the reflection of incident light on the surface of the solar cell, which based on the traditional anti-reflective layer. By the use of rigorous coupled wave algorithm (RCWA) and equivalent medium theory (EMT), the new structure was analyzed and the correctness of the results was obtained.The main work of this paper focus on the following aspects:1. By analyzing the traditional one-layer and multilayer anti-reflective layer, this paper put forward the importance of studying sub-wavelength grating anti-reflective layer.2. Some methods were presented in this paper to analyze the sub-wavelength grating, such as the rigorous coupled wave algorithm (RCWA) and the equivalent medium theory (EMT). And the factors were also analyzed which influence the anti-reflective characteristics of sub-wavelength grating.3. A novel sub-wavelength grating anti-reflective structure was designed through etching the surface of the silicon film and attaching the S13N4film and SiO2film above the one-dimensional grating. It is found that a low reflectivity in a wide incident angle and incident wavelength has been obtained.4. By using the two-dimensional sub-wavelength grating in the anti-reflective structure, we designed a new two-dimensional anti-reflective structure which has lower reflectivity than the one-dimensional grating in a wide incident angle and incident wavelength. In this paper, we designed two kinds of novel sub-wavelength grating antireflective structures based on the summary of the previous research. By using the RCWA and EMT, we analyzed the new anti-reflective structure. The results showed that:these results are basically identical, and low reflectivity can be achieved in the new anti-reflective layer in a wider incidence angle and incident wavelength.