Researchers from the Chinese Academy of Sciences (CAS), Hebei University of Science and Technology, Hebei University of Engineering, North China Electric Power University, Anhui Institute of Innovation for Industrial Technology, University of Science and Technology of China, Hefei University of Technology and Liaocheng University have used Lauramide (LA) molecules on perovskite films as a surface modification layer. As a result, the team demonstrated a multifunctional surface molecular modification strategy to develop high-efficiency perovskite solar cells.
By depositing the layer of LA molecule, the defects on the perovskite surface were successfully passivated. LA can form hydrogen bonds with iodide ions (I−) and promote anchoring to impede the migration of I− inside the crystal structure. The lone electron pair of the carbonyl (C=O) functional group in LA can also coordinate with the uncoordinated lead ions (Pb2+) or lead clusters (Pb0), which effectively reduces the non-radiative recombination caused by surface defects.
Benefiting from the multiple functions of LA molecule, including its passivation of defects and its long alkyl chains that mitigate accelerated aging and degradation triggered by moisture, the PCE of the resulting treated device was significantly improved to 25.2%. In addition, the PSC maintained over 92% of its initial efficiency after 1000 h of exposure to a relative humidity (RH) of 65 ± 5%.
