Inter-Fullerene Electronic Coupling Controls the Efficiency of Photoinduced Charge Generation in Organic Bulk Heterojunctions
- Department of Chemistry, Colorado State University, 200 W Lake Street Fort Collins CO 80523 USA; Chemistry and Nanoscience Center, National Renewable Energy Laboratory, 15013 Denver West Parkway Golden CO 80401 USA
- Chemistry and Nanoscience Center, National Renewable Energy Laboratory, 15013 Denver West Parkway Golden CO 80401 USA
- Chemistry and Nanoscience Center, National Renewable Energy Laboratory, 15013 Denver West Parkway Golden CO 80401 USA; Department of Chemistry and Physics, Warren Wilson College, Swannanoa NC 28778 USA
- Liebniz Institute for Solid State and Materials Research, Dresden D01069 Germany
- Department of Chemistry, Colorado State University, 200 W Lake Street Fort Collins CO 80523 USA
Photoinduced charge generation (PCG) dynamics are notoriously difficult to correlate with specific molecular properties in device relevant polymer:fullerene organic photovoltaic blend films due to the highly complex nature of the solid state blend morphology. Here, this study uses six judiciously selected trifluoromethylfullerenes blended with the prototypical polymer poly(3-hexylthiophene) and measure the PCG dynamics in 50 fs-500 ns time scales with time-resolved microwave conductivity and femtosecond transient absorption spectroscopy. The isomeric purity and thorough chemical characterization of the fullerenes used in this study allow for a detailed correlation between molecular properties, driving force, local intermolecular electronic coupling and, ultimately, the efficiency of PCG yield. The findings show that the molecular design of the fullerene not only determines inter-fullerene electronic coupling, but also influences the decay dynamics of free holes in the donor phase even when the polymer microstructure remains unchanged.
- Research Organization:
- National Renewable Energy Lab. (NREL), Golden, CO (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES)
- DOE Contract Number:
- AC36-08GO28308
- OSTI ID:
- 1337538
- Report Number(s):
- NREL/JA-5900-67262
- Journal Information:
- Advanced Energy Materials, Vol. 6, Issue 24; ISSN 1614-6832
- Publisher:
- Wiley
- Country of Publication:
- United States
- Language:
- English
Similar Records
Free Carrier Generation in Organic Photovoltaic Bulk Heterojunctions of Conjugated Polymers with Molecular Acceptors: Planar versus Spherical Acceptors
Light-induced EPR study of charge transfer in poly(3-hexylthiophene)/fullerene bulk heterojunction