Nanostructured anti-reflection coating for absorption enhancement in perovskite silicon tandem solar cells

Perovskite-silicon tandem solar cells have captured the attention of the solar cell research community due to the advantages of perovskites, such as, an easy fabrication process using sol-gel methods and silicon bottom cells that can be fabricated using well-established fabrication techniques. The present study discusses the design, optimization, and numerical analysis related to the role of nanostructured anti-reflection coating design for perovskite (MAPbI₃) silicon tandem solar cells. In the design, the top cell is taken as MAPbI₃ and the bottom cell is C-silicon. The anti-reflection coating is designed with SiO₂ nanoparticles embedded in ITO. These nanostructured top anti-reflection coating results are compared with its planar top cell counterpart. SiO₂ nanoparticle diameter and interparticle separation are optimized to get maximum absorption in the top cell. Upon optimization, it was found that a design having SiO₂ nanoparticles with a diameter of 60 nm and no interparticle separation showed the most reduction in reflection, which in turn led to an increase in absorption in the top cell. The proposed structure enhances current density by 8.3% over the planar cell. This top cell current is matched to the bottom silicon thickness. These findings were validated using Mie scattering and the Bruggmann effective medium approximation.