Evolutionary optimization of TCO/mesh electrical contacts in CIGS solar cells

State of the art solar cells often require a combination of TCO and metallic grid to efficiently transport the generated current to an external circuit. Optimization of these complex contacts based on several materials with different conductivities and geometries is often still based on a traditional approach consisting of simple analytical formulas and empirical knowledge in spite of the complexity. An evolutionary algorithm combined with an electrical 2D+1D FEM model is used to optimize the shape of the metallic contact considering the material conductivities, the geometry and shadowing. The performance of two automatically designed contacts is compared with experimental results of CIGS solar cells prepared with two different TCO thicknesses