New multilayer film photonic crystal grating multilayer anti-reflection layer for visible-near-infrared solar cells

In this paper, a new anti-reflection layer(ARL) is designed by the finite element method, which is made of parabolic air slots with periodic distribution etched on a multilayer film structure with optimized thickness. The effective transmissivity in the 400-1450 nm band is formulated in conjunction with the AM1.5 solar spectrum, and the effects of the air slot depth (H), depth-to-width ratio, and the size of a period (T) on the transmissivity of the ARL are investigated separately. By optimizing the structural parameters, a new type of ARL with H = 310 nm and T = 105 nm acting in the 400-1450 nm waveband was obtained. The transmissivity of this stacked structure ARL is improved and the stability of the transmission effect in the full waveband is enhanced compared to the conventional membrane structure and the emerging micro-nano-optical structure. The effective transmissivity of this multilayer film photonic crystal grating ARL is calculated to be 98.43% in the operating full waveband (400-1450nm) of the Si-0.86 eV PbS double-junction solar cell. The transmissivity is higher than 93.83% of multilayer film ARL and 97.13% of TiO2 grating ARL.