Abstract
One of the promising approaches to improve the efficiency of conventional single-crystalline silicon (c-Si) solar cells is their integration in a tandem arrangement. In this perspective, inorganic–organic perovskites are an ideal blend of materials to combine with c-Si owing to their complementary light absorption characteristics. Even though interesting and promising combinations of perovskite/c-Si-based solar cells have been presented, their overall efficiency has been limited by the photocurrent reduction occurring in both perovskite and silicon due mostly to reflection and parasitic losses. Here, we envision and model a new design strategy for an efficient light-to-current conversion through the use of a nanopillar array based perovskite/c-Si tandem solar cell. The optical–electrical performance of the proposed architecture is analyzed by a 3D finite-element numerical model. In particular, we have searched for the best optical enhancement conditions through the tuning of the cell geometrical parameters, demonstrating the importance of optical resonances. Afterward, we have evaluated the electrical response of the optimized structures in a four-terminal (4-T) configuration by studying the current–voltage characteristics and power conversion efficiency. In particular, the introduced solar cell yields a conversion efficiency of 27%, with contributions of 18.5% and 8.51% from perovskite and c-Si, respectively. We have compared our proposed nanopatterned design with its planar counterpart characterized by the same quantity of active material, obtaining a relative efficiency enhancement of 21%. Importantly, the conversion efficiency of our proposed design surpasses the efficiency of single-junction perovskite and c-Si solar cells, and, similarly, it represents a new achievement for 4-T perovskite/c-Si tandem solar cells.