Publication date: 21st July 2025
Tin–lead (Sn–Pb) perovskites are promising materials for next-generation photovoltaics. However, their practical application is hindered by poor stability: Sn²⁺ readily oxidizes to Sn⁴⁺ under oxygen, moisture, processing solvents, or native oxidants such as I₂ [1]. This oxidation generates surface defects in the perovskite that act as non-radiative recombination centers, resulting in significant open-circuit voltage (Voc) losses in these technologies. To address this challenge, we propose the use of passivation agents designed to lower defect density and mitigate interfacial carrier losses. Our strategy preserves the anion framework while systematically tuning the cation composition. In this study, we focus on the tetrafluoroborate (BF₄⁻) family of additives, whose anions can passivate surface defects in perovskites [2].
This passivation leads to higher open-circuit voltage and improved fill factor which enhances device performance and supports progress toward efficient, stable Sn–Pb perovskite solar cells.
S. Daim would like to thank the “Initiative on Energy Research”, founded by University Mohammed VI Polytechnic, for the financial support through the project “Toward efficient, stable, environmentally friendly, and scalable Perovskite Solar Cells”, as well as the Institute of Advanced Materials (INAM), University Jaume I, for their support.