Cutting sinusoidal gratings to enhance light trapping in thin-film silicon solar cells

Abstract

A crystalline silicon thin-film solar cell with a three-layer sinusoidal grating structure is studied. The structure has a double-layer antireflection layer, and the three-layer grating is located in the double-layer antireflection layer and the passivation layer, respectively. The related parameters of the grating structure are optimized by scanning using finite-difference time-domain. The optimization results show that cutting the sinusoidal grating structure can significantly improve the light absorption efficiency of the cell for near-infrared light (750–1100 nm), and the enhancement effect is mainly in the transverse electric (TE)-polarized light. This is because the localized surface plasmon resonance and optical waveguide mode under TE-polarized light can be fully excited after the sinusoidal structure is cut. The short-circuit current density ( J S C ) of the optimized three-layer sinusoidal grating structure is 19.82 m A / c m 2 , which is 112.43% higher than that of the planar structure with the same parameters and 23.18% higher than that of the uncut sinusoidal grating structure with the same parameters.