Optical simulation of low aspect ratio hemisphere array surface texturing for crystalline Si film solar cells

Nano-hemisphere arrays with low aspect ratios are proposed to texture ultrathin poly-Si film-based solar cells. The calculation indicates that the ultimate efficiency can reach as high as ∼30% (almost 2 times of 15.9% for a 2 μm thick flat film) when the optimized nano-hemisphere array with both the array periodicity and hemisphere diameter of 0.6 μm is incorporated into a 0.3 μm thick poly-Si film. The underlying physics responsible for performance enhancement is discussed.