[8a-E201-1~11] 12.5 Organic, Perovskite, and hybrid solar cells

10:00 AM - 10:15 AM JST(1:00 AM - 1:15 AM UTC)

[8a-E201-5] Electron-Accepting Properties of Fullerenes Diffused into Perovskite Layer and the Origin of their High Electron Collection Capability

〇Ryota Tozaki¹, Masato Iwasawa², Hiroyuki Yoshida^1,3 (1.Chiba Univ., 2.Nissan Chemical, 3.Chiba Univ.)

Keywords:

Perovskite Solar Cells,Fullerene

Fullerene derivatives exhibit exceptionally high power conversion efficiencies as electron transport layers (ETLs) in inverted perovskite solar cells. To clarify the origin of their superiority, we investigated the electronic states of C₆₀ and PTCDA molecules diffused into CH₃NH₃PbI₃ (MAPbI₃) using gas cluster ion beam-assisted ultraviolet photoelectron spectroscopy (GCIB-UPS) and X-ray photoelectron spectroscopy (GCIB-XPS). We found that the diffused ETL molecules accept electrons from MAPbI₃, become negatively charged, and contribute to defect passivation. Furthermore, by reanalyzing UPS and low-energy inverse photoelectron spectroscopy (LEIPS) spectra, we found that C₆₀ exhibits a smaller on-site Coulomb energy than PTCDA. These results suggest that the superior electron-accepting ability of fullerenes, arising from their small on-site Coulomb interaction, is a key factor underlying their excellent electron-collection properties and high photovoltaic performance.