Buried interface passivation with bis(3-aminopyrid-2-yl) sulfide for carbon-based perovskite solar cells

Abstract

Electron layer defects are one of the key factors affecting the performance of perovskite solar cells (PSCs). In this work, high efficiency for PSCs was achieved by using bis(3,3-2-aminopyridine) sulfide (BSL) for buried interface modification of the electron layer. Considering that the S atom connecting the pyridine ring and the N atom on the pyridine ring have a negative electron concentration region, they passivate the oxygen defect of SnO₂. The BSL also forms a coordination effect with Pb²⁺ and I⁻ in the perovskite, thus passivating the Pb²⁺ and I⁻ defects. The champion power conversion efficiency of the BSL as a buried interface increased to 16.91%, and the unencapsulated device retained 89.77% of its initial efficiency when it was stored in an ambient atmosphere after 768 h. The strategy of the buried interface passivation provides a reference for enhancing the power conversion efficiency and stability of carbon-based perovskite solar cells.