Enhancement of optical absorption in the amorphous silicon solar cell with periodic wave grating structure

We report on the design of amorphous silicon solar cells with the periodic wave grating structures. Optical absorption in TF a-Si solar cells is studied numerically via the rigorous coupled wave analysis (RCWA) enhanced by the modal transmission line (MTL) theory. The impact of period of the wave gratings is investigated. The result shows that the studied wave grating structure can promote the absorption in wavelength of 0.4-0.65 μm under any periods; clearer absorption gains emerge in wavelength range of 0.65-0.84 μm when periods of 0.3-0.7 μm are chosen. The integral for the absorbance spectrum of each model shows that the absorption gains reach up to the highest point in period of 0.5 μm, which is 46.44%.