Optimization of Multi-Layer Antireflection Coatings for Multicrystalline Silicon Solar Cells

Abstract

This paper aims at developing a design strategy of multi-layer antireflection coatings (ARCs) to improve the optical performance for multicrystalline silicon (mc-Si) solar cells. We proposed a three-dimensional (3D) ellipsoid surface model to represent the concave-like morphology formed by acidic texturization. Monte Carlo ray tracing algorithm was applied to simulate the interaction between incident light and wafer. After that, we fixed the parameters of the 3D model by fitting the simulated reflectance to the measured result of a typical industrial mc- Si wafer. The reflectance and transmittance of multi-layer ARC over 300 nm to 1100 nm were calculated by employing transfer-matrix-method (TMM). The validity of the simulation was proved by the agreement between simulated and measured reflectance of silicon nitride (SiNx:H) single-layer ARC. Finally, we studied a triple-layer stack, including bottom and intermediate layers of SiNx with high and medium refractive indexes respectively and a top layer of SiO2. Genetic algorithm was employed to optimize the thicknesses of the three layers. Calculated result showed that the designed stack can increase the short circuit current by 1.12 mA/cm2.