Improving the Solar Energy Utilization of Perovskite Solar Cells via Synergistic Effects of Alkylamine and Alkyl Acid on Defect Passivation

Defects in perovskite film are sources of charge recombination centers, which are detrimental to the performance of perovskite solar cells (PSCs). To decrease the density of defects, dodecylamine (DAM), dodecylic acid (DAC), and 12-aminolauric acid (ALA) are utilized as additives to prepare methyl ammonium lead iodide (MAPbI(3)) perovskite films. Herein, the passivation effects of these molecules on the properties of the MAPbI(3) films and the performances of the corresponding PSCs are studied. The results show that DAM and DAC which contain -NH2 and -COOH groups, respectively, can increase the PCEs of the devices. This result implies that both groups serve as the Lewis base, passivating the defects of undercoordinated Pb2+. For the ALA molecules, the -NH2 and -COOH groups are present simultaneously at the two ends of the molecule; the passivation ability is more significant than the others, which is attributable to the synergistic effects of the two groups. By the passivation of ALA, the PCE of the PSC can increase from 18.42% to 19.96% under one sun illumination. Furthermore, the treatments of the passivation agents also increase the hydrophobicity of the perovskite films, improving the stability of the PSCs.

Automated summary

To reduce the density of defects in perovskite solar cells, dodecylamine (DAM), dodecylic acid (DAC), and 12-aminolauric acid (ALA) were used as additives to prepare perovskite films. The results showed that DAM and DAC could increase the device's power conversion efficiency (PCE), while ALA exhibited more significant passivation effects due to the synergistic effects of its -NH2 and -COOH groups. Additionally, the treatments with passivation agents also improved the hydrophobicity of the perovskite films, enhancing the stability of the solar cells.