title: Room-temperature, solution-processable organic electron extraction layer for high-performance planar heterojunction perovskite solar cells.
abstract: In this work, we describe a room-temperature, solution-processable organic electron extraction layer (EEL) for high-performance planar heterojunction perovskite solar cells (PHJ PVSCs). This EEL is composed of a bilayered fulleropyrrolidinium iodide (FPI)-polyethyleneimine (PEIE) and PC61BM, which yields a promising power conversion efficiency (PCE) of 15.7% with insignificant hysteresis. We reveal that PC61BM can serve as a surface modifier of FPI-PEIE to simultaneously facilitate the crystallization of perovskite and the charge extraction at FPI-PEIE/CH3NH3PbI3 interface. Furthermore, the FPI-PEIE can also tune the work function of ITO and dope PC61BM to promote the efficient electron transport between ITO and PC61BM. Based on the advantages of room-temperature processability and decent electrical property of FPI-PEIE/PC61BM EEL, a high-performance flexible PVSC with a PCE ∼10% is eventually demonstrated. This study shows the potential of low-temperature processed organic EEL to replace transition metal oxide-based interlayers for highly printing compatible PVSCs with high-performance.
authors.affiliation: Department of Chemical Engineering Education, Chungnam National University, 99 Daehak-ro, Yuseong-gu, 305-764, South Korea.
authors.forename: Jong H
authors.initials: JH
authors.lastname: Kim
authors.forename: Chu-Chen
authors.initials: CC
authors.lastname: Chueh
authors.forename: Spencer T
authors.initials: ST
authors.lastname: Williams
authors.forename: Alex K-Y
authors.initials: AK
authors.lastname: Jen