A short series of alkyl substituted perylenediimides (PDIs) with varying steric bulk are used to demonstrate the relationship between molecular structure, materials properties, and performance characteristics in organic photovoltaics. Devices were made with the structure indium tin oxide/copper phthalocyanine (200 Å)/PDI (200 Å)/bathocuproine (100 Å)/aluminum (1000 Å). We found that PDIs with larger substituents produced higher open circuit voltages (VOC's) despite the donor acceptor interface gap (Δ EDA) remaining unchanged. Additionally, series resistance was increased simultaneously with VOC the effect of reducing short circuit current, making the addition of steric bulk a tradeoff that needs to be balanced to optimize power conversion efficiency. © 2011 American Institute of Physics.
|Original language||English (US)|
|Journal||Applied Physics Letters|
|State||Published - Jun 4 2011|
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledged KAUST grant number(s): GPEC-2006, KUS-C1-015-21
Acknowledgements: The authors thank Cody W. Shlenker and M. Dolores Perez for helpful discussion and acknowledge the Global Photonic Energy Corporation (Award No. GPEC-2006) and the Center for Advanced Molecular Photovoltaics (Award No. KUS-C1-015-21), made by King Abdullah University of Science and Technology (KAUST).
This publication acknowledges KAUST support, but has no KAUST affiliated authors.