Effective Light Absorption Using the Double-sided Pyramid Gratings for Thin-Film Silicon Solar Cell

The design of double-sided pyramid grating structure can be used to enhance broadband light absorption. The front grating can greatly reduce the light reflection, especially in the short-wavelength region, and the rear grating can also achieve that same effect in the longer wavelength region. In the paper, for the double-sided pyramid grating structure, the photon absorption distribution of each part is studied and compared with the bare crystalline silicon. Theoretical results show that, by reasonably adjusting the structure parameters of the double-sided grating, the light reflection of the whole band can be reduced greatly which is beneficial for black silicon formation and the total light absorption is also increased. However, further studies have shown that using the rear grating does not improve the effective light absorption of the crystalline silicon.