An optical study of ceramic substrate for solar cells: effect of buffer layer

An optical model was proposed to describe the scattering properties of a Lambertian ceramic reflector with an overlayer. It reveals that the overlayer can markedly modify the light scattering properties of the substrate. This means a buffer layer (BL) between Si layer and ceramic substrate in a solar cell affects optical confinement of the cell. It turns out that the BL having a lower refractive index than the substrate is not suitable, especially when refractive index of the substrate is high. Optical confinement can be slightly enhanced provided that the BL thickness and refractive index were optimized.