Reducing optical reflection loss through textured PEDOT:PSS in hybrid Sn–Pb perovskite solar cells

Abstract

The recent surge of interest in Sn–Pb perovskite has largely increased due to its ideal band gap for single junction solar cells and suitability for incorporation into all-perovskite tandem solar cells. In this study, we focus on reducing the optical loss of Sn–Pb perovskite solar cells, specifically those with the ITO/PEDOT:PSS/Sn–Pb perovskite/C60/BCP/Ag inverted structure. This is achieved through the innovative application of a polystyrene (PS) sphere patterning method, used to create a textured surface on PEDOT:PSS. By adjusting the concentration of PS spheres in PEDOT:PSS, the textured device showed a 7% increase in photocurrent compared to its planar counterpart. This led to an enhanced power conversion efficiency of 21.0%, which further improved to 21.6% when an anti-reflection coating was applied to the glass side. Further confirmation of these benefits is demonstrated through a significant increase in external quantum efficiency (EQE) response. This result mirrors the reduction in reflectance and enhancement in light absorption exhibited by the textured layer. The findings of this study present an easy method for creating textured PEDOT:PSS and highlight its crucial role in reducing optical loss during the development of Sn–Pb perovskite solar cells.