Light confinement for silicon solar cells with thin substrate

Thinner silicon substrate are expected to be used in silicon solar cells for cost reduction. In this contribution, we numerically discussed a series antireflection structure for light confinement design that may be applied to silicon solar cells with thin substrates. The results show that nano-pillar-array with silicon nitride coating has a very low reflectance over the whole response region of silicon solar cells. The average reflectance could reach 2.34%, which is fundamentally coincident with reported experimental results. Planar reflection at the back surface of the cell was investigated for light confinement application. Enhanced light absorption of the cell has achieved with high reflectance of the back surface, while the front surface reflectance also increased prominently. Based on the simulation results, back surface scattering with high reflectance were proposed for better light confinement in silicon solar cells with thin substrates.