Hydroxylated non-fullerene acceptor for highly efficient inverted perovskite solar cells. Issue 12 (11th November 2021)

• Record Type: Journal Article
• Authors: Yang, Qing; Liu, Xuan; Yu, Shuwen; Feng, Zhendong; Liang, Lixin; Qin, Wei; Wang, Youyang; Hu, Xiaobo; Chen, Shaoqiang; Feng, Zhaochi; Hou, Guangjin; Wu, Kaifeng; Guo, Xin; Li, Can
• Is Part Of: Energy & environmental science. Volume 14:Issue 12(2021)
• Page Start: 6536
• Page End: 6545
• Publication Date: 2021-11-11
• Subjects: Energy conversion -- Periodicals; Fuel switching -- Periodicals; Environmental sciences -- Periodicals; Environmental chemistry -- Periodicals; 333.79
• DOI: 10.1039/d1ee02248b
• Languages: English
• ISSNs: 1754-5692

Abstract

Abstract : A hydroxylated non-fullerene acceptor (NFA) is developed to modify the interface between the perovskite and the electron transport layer in inverted perovskite solar cells (i-PSCs), achieving a record PCE of 22.09% among reported i-PSCs employing NFAs. Abstract : Inverted perovskite solar cells (i-PSCs) manifest negligible hysteresis and potential to construct tandem solar cells attracting much attention, but their power conversion efficiency (PCE) still lags behind those of conventional ones due to non-radiative recombination from defect states and mismatched energy-level alignment for electron transport. Herein, we report on employing a hydroxylated non-fullerene acceptor (NFA), termed IT-DOH, to modify the interface between the perovskite and the electron transport layer (ETL) for reduced defects and improved electron transport. Compared with –CN and –CO groups in the parent molecule ITIC, additional –OH groups in IT-DOH can further suppress defect states by interacting with undercoordinated Pb 2+ . More importantly, the conjugated planes of IT-DOH can be elongated by intermolecular hydrogen-bonding interactions, leading to a long-range-ordered molecular arrangement and face-on orientation, which facilitates the electron transport from the perovskite to the ETL through IT-DOH molecules. Consequently, a record PCE of 22.09% among reported i-PSCs modified by NFAs is achieved from IT-DOH-treated i-PSCs. Our work highlights the importance of molecular ordering and orientation of the NFAs as interfacial materials, and provides a guideline to design NFAs by hydroxylation for highly efficient and stable i-PSCs.