Design and Optimization of CIGS-Based Solar Cell with Surface Dielectric Nanostructures Arrangement

This study introduces an advanced design for copper indium gallium selenide (CIGS) thin-film solar cells by incorporating aluminum arsenide (AlAs) dielectric nano-particles on the front surface. Three nanoparticle geometries—cubic, cylindrical, and spherical—are explored to enable broadband light absorption and enhance overall device efficiency. The optimization of structural parameters is performed using the particle swarm optimization (PSO) algorithm in conjunction with the Lumerical finite-difference time-domain (FDTD) solver. Simulation results demonstrate that the cubic nanoparticle design delivers the highest performance, achieving an average absorption of 93.5%, corresponding to 31.7% improvement over the baseline cell. In comparison, the cylindrical and spherical designs yield average absorptions of 90.1% (26.9% enhancement) and 88.4% (24.5% enhancement), respectively. The enhanced performance of cubic AlAs nano-particles arises from their support of broadband, high-order Mie resonances, enabled by sharp edges and flat facets. These features boost light scattering and near-field coupling into the CIGS layer, while refractive index matching with ZnO improves the optical impedance with enhanced light confinement and reduced reflection. Considering recombination mechanisms, the power conversion efficiencies (PCEs) of the proposed cubic-, cylindrical, and spherical-based structures are enhanced to 17.6%, 16.18%, and 16.70%, respectively, compared to the conventional design of 12.56%. The reported surface-integrated dielectric nanostructure approach demonstrates strong potential for high-efficiency thin-film solar cells with reduced material usage, lower fabrication complexity, and cost-effectiveness.