Optical optimization of ultra-thin crystalline silicon solar cells by a co-simulation approach of FEM and GA

Both the shape and size of embedded Ag nanoparticles are crucial parameters to boost the optical efficiencies of Si solar cells. Herein, by a co-simulation approach of finite element method and genetic algorithm, we optimized the optical properties of four different types of ultra-thin crystalline silicon (c-Si) solar cells containing Ag nanoparticles (nano-cuboids, -cylinders, -pyramids and -cones). The synergistic plasmon effects of electromagnetic near-field enhancements and far-field scattering of Ag nanoparticles are revealed to account for the enhanced absorption and photocurrent of these cells. The optimal photocurrent is predicted to be similar to 2.67 and 1.51 fold higher than that of flat reference and literature report, respectively. In addition, the generation rates of charge carriers of the optimized cell are also discussed. The present work holds great promise for future design and applications of ultra-thin c-Si solar cells to further boost their optical efficiencies.