Fabrication of Pyramid/Porous Composite Structures for Mitigating Surface Optical Losses in Perovskite Solar Cells

This is the authors' abstract. We don't add key points for this paper.

Surface optical losses represent one of the critical factors limiting the photogenerated current density and power conversion efficiency (PCE) of perovskite solar cells (PSCs). To address this issue, this paper introduces a pyramid/porous composite structure on the light-facing surface of PSCs. The pyramids and porous structures are obtained on silicon surfaces via alkaline wet etching and metal-assisted chemical etching, respectively, and then replicated onto the cell surface using nanoimprint technology. The research findings indicate that the micrometer-scale pyramids induce multiple refractions of incident light, enhancing the probability of photons entering the interior of the cell. Moreover, the nanoscale porous structures on the pyramid mitigate the refractive index difference between air and the pyramid material, thereby reducing reflection losses for single-incident light. For the optimized pyramid/porous structure, a reduction in surface reflectivity from 40.3% to 5.1% is observed on silicon. Benefiting from the suppression of surface reflection losses by the pyramid/porous structure, the response spectrum of the PSCs is significantly improved. Consequently, the photogenerated current density of the device increases from 21.62 to 23.86 mA cm−2, with a relative enhancement in PCE by 9.5%.