4F-Phenethylammonium chloride as a key component for interfacial engineering of wide-bandgap perovskite absorber

The development of high-efficiency and stabilized tandem solar cells and solar cells for indoor light harvesting relies heavily on the fabrication of wide-bandgap (WBG) perovskite solar cells (PSCs) that exhibit exceptional efficiency and stability. In this study, we introduce an effective method for enhancing the optoelectronic properties of a 1.74 eV WBG perovskite absorber by interfacial engineering. Specifically, we utilize 4F-Phenethylammonium Chloride (4F-PEACL) as a key component for the surface treatment of perovskite layer. The treatment of perovskite with 4F-PEACL alters the surface stoichiometry, promoting self-doping and surface passivation, reducing surface recombination, and improving the optoelectronic properties of perovskite. Consequently, PCSs with perovskite treated with 4F-PEACL exhibit a notable power conversion efficiency of 20.27 %. Furthermore, the devices subjected to 4F-PEACL treatment demonstrate enhanced stability compared to the control devices across a range of testing settings. The findings of our study indicate that the utilization of organic salt perovskite passivation holds great potential in the development of efficient and stable WBG PSCs.