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Title: Inter-Fullerene Electronic Coupling Controls the Efficiency of Photoinduced Charge Generation in Organic Bulk Heterojunctions

Abstract

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.

Authors:
 [1];  [2];  [3];  [4];  [4];  [5];  [5];  [2];  [1]
  1. 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
  2. Chemistry and Nanoscience Center, National Renewable Energy Laboratory, 15013 Denver West Parkway Golden CO 80401 USA
  3. 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
  4. Liebniz Institute for Solid State and Materials Research, Dresden D01069 Germany
  5. Department of Chemistry, Colorado State University, 200 W Lake Street Fort Collins CO 80523 USA
Publication Date:
Research Org.:
National Renewable Energy Lab. (NREL), Golden, CO (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1337538
Report Number(s):
NREL/JA-5900-67262
Journal ID: ISSN 1614-6832
DOE Contract Number:
AC36-08GO28308
Resource Type:
Journal Article
Resource Relation:
Journal Name: Advanced Energy Materials; Journal Volume: 6; Journal Issue: 24
Country of Publication:
United States
Language:
English
Subject:
14 SOLAR ENERGY; 36 MATERIALS SCIENCE; charge separation; electronic coupling; fullerene; organic photovoltaics; polymer solar cells

Citation Formats

Larson, Bryon W., Reid, Obadiah G., Coffey, David C., Avdoshenko, Stanislav M., Popov, Alexey A., Boltalina, Olga V., Strauss, Steven H., Kopidakis, Nikos, and Rumbles, Garry. Inter-Fullerene Electronic Coupling Controls the Efficiency of Photoinduced Charge Generation in Organic Bulk Heterojunctions. United States: N. p., 2016. Web. doi:10.1002/aenm.201601427.
Larson, Bryon W., Reid, Obadiah G., Coffey, David C., Avdoshenko, Stanislav M., Popov, Alexey A., Boltalina, Olga V., Strauss, Steven H., Kopidakis, Nikos, & Rumbles, Garry. Inter-Fullerene Electronic Coupling Controls the Efficiency of Photoinduced Charge Generation in Organic Bulk Heterojunctions. United States. doi:10.1002/aenm.201601427.
Larson, Bryon W., Reid, Obadiah G., Coffey, David C., Avdoshenko, Stanislav M., Popov, Alexey A., Boltalina, Olga V., Strauss, Steven H., Kopidakis, Nikos, and Rumbles, Garry. 2016. "Inter-Fullerene Electronic Coupling Controls the Efficiency of Photoinduced Charge Generation in Organic Bulk Heterojunctions". United States. doi:10.1002/aenm.201601427.
@article{osti_1337538,
title = {Inter-Fullerene Electronic Coupling Controls the Efficiency of Photoinduced Charge Generation in Organic Bulk Heterojunctions},
author = {Larson, Bryon W. and Reid, Obadiah G. and Coffey, David C. and Avdoshenko, Stanislav M. and Popov, Alexey A. and Boltalina, Olga V. and Strauss, Steven H. and Kopidakis, Nikos and Rumbles, Garry},
abstractNote = {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.},
doi = {10.1002/aenm.201601427},
journal = {Advanced Energy Materials},
number = 24,
volume = 6,
place = {United States},
year = 2016,
month = 9
}
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