Multifunctional Modifications Based on Carbonyl Material Enhanced Performance of Perovskite Solar Cells

The rapid development of perovskite solar cells (PSCs) perovskite is inseparable from the investigation of plentiful new additive materials. Herein, a conjugated organic material called TPD-Br containing two carbonyl groups and Br atoms is synthesized. TPD-Br with Lewis-base groups can provide excellent passivation for defects between perovskite layer and electron transport layer. Furthermore, Br atom can also interact with iodine ions via halogen bonds. TPD-Br passivates the perovskite defects because it can interact with undercoordinated Pb 2+ ions by forming Pb  O bond, lower defect density and larger grain size occur in the perovskite can be obtained. Consequently, high-quality perovskite films with fewer defects can be fabricated. The PSCs with TPD-Br additive achieve a champion power conversion efficiency of 20.74%. These results illustrate that TPD-Br, as a superior passivate defect additive, can improve the performance and stability of PSCs.