Tuning Triplet-Pair Separation versus Relaxation Using a Diamond Anvil Cell

Grayson S. Doucette; Haw-Tyng Huang; Jason M. Munro; Kyle T. Munson; Changyong Park; John E. Anthony; Timothy Strobel; Ismaila Dabo; John V. Badding; John B. Asbury

Cell Reports Physical Science (Jan 2020)

Tuning Triplet-Pair Separation versus Relaxation Using a Diamond Anvil Cell

Grayson S. Doucette,
Haw-Tyng Huang,
Jason M. Munro,
Kyle T. Munson,
Changyong Park,
John E. Anthony,
Timothy Strobel,
Ismaila Dabo,
John V. Badding,
John B. Asbury

Affiliations

Grayson S. Doucette: Intercollege Materials Science and Engineering Program, Pennsylvania State University, University Park, PA 16802, USA; Department of Materials Science and Engineering, Pennsylvania State University, University Park, PA 16802, USA
Haw-Tyng Huang: Intercollege Materials Science and Engineering Program, Pennsylvania State University, University Park, PA 16802, USA; Department of Materials Science and Engineering, Pennsylvania State University, University Park, PA 16802, USA
Jason M. Munro: Intercollege Materials Science and Engineering Program, Pennsylvania State University, University Park, PA 16802, USA; Department of Materials Science and Engineering, Pennsylvania State University, University Park, PA 16802, USA
Kyle T. Munson: Department of Chemistry, Pennsylvania State University, University Park, PA 16802, USA
Changyong Park: HPCAT, X-ray Science Division, Argonne National Laboratory, Argonne, IL 60439, USA
John E. Anthony: Department of Chemistry, University of Kentucky, Lexington, KY 40506, USA
Timothy Strobel: Geophysical Laboratory, Carnegie Institution for Science, 5251 Broad Branch Road Northwest, Washington, DC 20015, USA
Ismaila Dabo: Intercollege Materials Science and Engineering Program, Pennsylvania State University, University Park, PA 16802, USA; Department of Materials Science and Engineering, Pennsylvania State University, University Park, PA 16802, USA
John V. Badding: Intercollege Materials Science and Engineering Program, Pennsylvania State University, University Park, PA 16802, USA; Department of Materials Science and Engineering, Pennsylvania State University, University Park, PA 16802, USA; Department of Chemistry, Pennsylvania State University, University Park, PA 16802, USA
John B. Asbury: Intercollege Materials Science and Engineering Program, Pennsylvania State University, University Park, PA 16802, USA; Department of Chemistry, Pennsylvania State University, University Park, PA 16802, USA; Corresponding author

Journal volume & issue: Vol. 1, no. 1
p. 100005

Abstract

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Summary: A tradeoff exists between triplet-pair separation versus relaxation that can limit the ability to utilize singlet fission for enhancing solar cell efficiency beyond the Shockley-Queisser limit. Here, we show that this tradeoff can be avoided in crystalline environments by studying a functionalized pentacene compressed in a diamond anvil cell. We demonstrate, using ultrafast transient absorption spectroscopy, that there is a “sweet spot” where the rate of triplet-pair separation can be accelerated by nearly an order of magnitude without causing fast excited state relaxation. X-ray diffraction and computational modeling allow us to quantify the corresponding increase of intermolecular coupling. Our findings suggest that increased coupling enhances excited state relaxation but that crystalline environments can suppress these relaxation processes in pentacene derivatives. The combination of these effects leads to the sweet spot and informs efforts to enhance triplet-pair separation rates in amorphous systems such as polymers.

Published in Cell Reports Physical Science

ISSN: 2666-3864 (Online)
Publisher: Elsevier
Country of publisher: United States
LCC subjects: Science: Physics
Website: https://www.cell.com/cell-reports-physical-science

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