At the atomistic level, we uncovered a dual-site passivation mechanism facilitated by sulfonamide molecules. These molecules effectively coordinate with undercoordinated atoms (dangling bonds) on the perovskite surface, thereby reducing defect densities and promoting improved crystallization. Together, these effects contribute to the realization of high-efficiency, high-stability perovskite solar cells.
As illustrated in the image above, sulfonamide molecules—specifically CN-BSA and CO-BSA—adopt a parallel binding configuration on the perovskite surface. In this arrangement, two functional groups within each molecule simultaneously interact with distinct undercoordinated surface atoms, enhancing both the material’s electronic properties and overall device performance.
This work is published in Advanced Materials.
Acknowledgement
This work is a result of close collaboration of experimentalists (Prof Jun Peng’s group) and theorists (the nexSAS group). We acknowledge the financial support from ACAP and the computational resource from the National Computational Infrastructure of Australia.