Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Crucial role of fluorine in fully alkylated ladder type carbazole based nonfullerene acceptors for efficient organic solar cells

Published

Author(s)

Eliot Gann, Christopher McNeill, He Qiao, Munazza Shahid, Xuchem Jiao, Flurin D. Eisner, Tingmang Wu, Zhuping Fei, Thomas D. Anthopoulos, Martin Heeney

Abstract

Two fused ladder type nonfullerene acceptors, DTCCIC and DTCCIC-4F, based on an electron-donating core alkylated dithienocyclopentacarbazole flanked by electron-withdrawing non-fluorinated or fluorinated 1,1- dicyanomethylene-3-indanone (IC or IC-4F), are designed, synthesized, and applied in organic solar cells (OSCs). The two new molecules reveal planar structures and strong aggregation behavior. OSCs based on DTCCIC-4F exhibit a power conversion efficiency of 12.6%, much higher than that of DTCCIC based devices (6.2%). Microstructural studies reveal that while both acceptors are highly crystalline, bulk heterojunction blends based on the non- fluorinated DTCCIC result in overly coarse domains, while blends based on the fluorinated DTCCIC- 4F exhibit a more optimal nanoscale morphology. Our results demonstrate that fluorine in DTCCIC-4F can help balance molecular aggregation that leads to efficient charge separation and mobility, but not so excessive that leads to excessive phase separation, which is crucial to achieve high performance OSCs.
Citation
ACS Applied Materials and Interfaces

Keywords

Solar Cells, RSoXS, resonant scattering

Citation

Gann, E. , McNeill, C. , Qiao, H. , Shahid, M. , Jiao, X. , Eisner, F. , Wu, T. , Fei, Z. , Anthopoulos, T. and Heeney, M. (2020), Crucial role of fluorine in fully alkylated ladder type carbazole based nonfullerene acceptors for efficient organic solar cells, ACS Applied Materials and Interfaces, [online], https://doi.org/10.1021/acsami.0c00981 (Accessed March 5, 2024)
Created January 30, 2020, Updated October 14, 2022