Optimization And Design For Solar Cells Based On Grating Structure And Surface Plasmon

As solar cells can convert sunlight into electrical energy by photovoltaic effect, it has been a great way to solve the energy problem and generate new green energy. However, low light conversion efficiency and high production costs are the biggest problems restricting the development of solar cells. Current research on solar cells mainly in the following two points: One is in study of new materials of solar cells to improve the photoelectric conversion efficiency. The other is by optimizing the design of solar cells window layer, the absorption layer and the anti-back layer to improve the absorption efficiency and the cost performanceof the solar cells.This paper is to optimize and design the structure of absorption layer of solar cells. The study of solar cells mainly in the following two aspects:(1)A variety of grating structures have been designedin the CdTe thin-film layer. By optimizing the filling ratio and the groove depth, the new type of grating of single and double filling ratios in the absorption were designed. By applying FEM method,the absorption efficiency in the range of 250nm~1000 nm has been analyzed for CdTe layer with rectangular and rectangular with double filling ratios grating.The results show that the absorption efficiency of the single filling ratioand double filling ratios grating structures can be improved more than the flat absorption layer. The average absorption rate of double filling ratios grating increased by at least 10% over non patterned in the range of almost all visible spectrum. The results indicate that,by designing the structure, random reflection photonic in grating increases the effect of time and distance in the light absorption layer,and finally improves the photo electric conversion efficiency of the thin-film solar cells.(2)The metal nanoparticles were added to the grating structure of GaAs absorption layer. It utilizes the effect of metal surface plasmon which highly localized sunlight in the range of nanometer size in the GaAs absorption layer. Thereby, it can improve the photoelectric conversion efficiency of solar cells. For different shapes, it has been studied rectangle, triangle and spherical nanoparticles. By analyzing and optimizing theparameters of the three graphics,the parameters of the maximum absorption were found. By applying FEM method,the absorption efficiency in the range of 250nm~1000 nm has been analyzed for the structure of three shapes in the absorption layer. The results show that in the range of 250nm~450nm, the absorption rates of three structures are almost the same. In the range of 450nm~750nm, the absorption rate of spherical structure is higher than rectangle and triangle structure. And the absorption rate of rectangle structure is lower than triangle and spherical structure. In the range of 750nm~1000nm, the absorption rates of the structures vary widely. The average absorption rate of the rectangle structure is higher than triangle and spherical structure.Overall, for the three structures of different shapes, the average absorption rate of the spherical structure is higher than rectangle and triangle structurein the sunlight spectrum of visible light.