Evidence for strong and weak phenyl-C61-butyric acid methyl ester photodimer populations in organic solar cells
File(s)
Accepted version
Author(s)
Type
Journal Article
Abstract
In polymer/fullerene organic solar cells, the photochemical dimerization of phenyl-C61-butyric acid methyl ester (PCBM) was reported to have either a beneficial or a detrimental effect on device performance and stability. In this work, we investigate the behavior of such dimers by measuring the temperature dependence of the kinetics of PCBM de-dimerization as a function of prior light intensity and duration. Our data reveal the presence of both “weakly” and “strongly” bound dimers, with higher light intensities preferentially generating the latter. DFT simulations corroborate our experimental findings and suggest a distribution of dimer binding energies, correlated with the orientation of the fullerene tail with respect to the dimer bonds on the cage. These results provide a framework to rationalize the double-edged effects of PCBM dimerization on the stability of organic solar cells.
Date Issued
2019-08-27
Date Acceptance
2019-05-01
Citation
Chemistry of Materials, 2019, 31 (16), pp.6076-6083
ISSN
0897-4756
Publisher
American Chemical Society (ACS)
Start Page
6076
End Page
6083
Journal / Book Title
Chemistry of Materials
Volume
31
Issue
16
Copyright Statement
© 2019 American Chemical Society
Subjects
Science & Technology
Physical Sciences
Technology
Chemistry, Physical
Materials Science, Multidisciplinary
Chemistry
Materials Science
PHOTOCHEMICAL TRANSFORMATION
C-60
POLYMER
DIMERIZATION
GENERATION
STABILITY
EXCITON
Materials
03 Chemical Sciences
09 Engineering
Publication Status
Published
Article Number
acs.chemmater.8b05194
Date Publish Online
2019-05-16