Columbia Univ., New York, NY (United States). Dept. of Chemistry; OSTI
Columbia Univ., New York, NY (United States). Dept. of Chemistry
City Univ. of New York (CUNY), NY (United States). Photonics Initiative; City Univ. of New York (CUNY), NY (United States). Graduate Center. Dept. of Physics
Singlet fission (SF) is an exciton multiplication process with the potential to raise the efficiency limit of single junction solar cells from 33% to up to 45%. Most chromophores generally undergo SF as solid-state crystals. However, when such molecules are covalently coupled, the dimers can be used as model systems to study fundamental photophysical dynamics where a singlet exciton splits into two triplet excitons within individual molecules. Here we report the synthesis and photophysical characterization of singlet fission of a hexacene dimer. Comparing the hexacene dimer to analogous tetracene and pentacene dimers reveals that excess exoergicity slows down singlet fission, similar to what is observed in molecular crystals. Conversely, the lower triplet energy of hexacene results in an increase in the rate of triplet pair recombination, following the energy gap law for radiationless transitions. These results point to design rules for singlet fission chromophores: the energy gap between singlet and triplet pair should be minimal, and the gap between triplet pair and ground state should be large.
Sanders, Samuel N., et al. "Singlet fission in a hexacene dimer: energetics dictate dynamics." Chemical Science, vol. 11, no. 4, Dec. 2019. https://doi.org/10.1039/c9sc05066c
Sanders, Samuel N., Kumarasamy, Elango, Fallon, Kealan J., Sfeir, Matthew Y., & Campos, Luis M. (2019). Singlet fission in a hexacene dimer: energetics dictate dynamics. Chemical Science, 11(4). https://doi.org/10.1039/c9sc05066c
@article{osti_1816620,
author = {Sanders, Samuel N. and Kumarasamy, Elango and Fallon, Kealan J. and Sfeir, Matthew Y. and Campos, Luis M.},
title = {Singlet fission in a hexacene dimer: energetics dictate dynamics},
annote = {Singlet fission (SF) is an exciton multiplication process with the potential to raise the efficiency limit of single junction solar cells from 33% to up to 45%. Most chromophores generally undergo SF as solid-state crystals. However, when such molecules are covalently coupled, the dimers can be used as model systems to study fundamental photophysical dynamics where a singlet exciton splits into two triplet excitons within individual molecules. Here we report the synthesis and photophysical characterization of singlet fission of a hexacene dimer. Comparing the hexacene dimer to analogous tetracene and pentacene dimers reveals that excess exoergicity slows down singlet fission, similar to what is observed in molecular crystals. Conversely, the lower triplet energy of hexacene results in an increase in the rate of triplet pair recombination, following the energy gap law for radiationless transitions. These results point to design rules for singlet fission chromophores: the energy gap between singlet and triplet pair should be minimal, and the gap between triplet pair and ground state should be large.},
doi = {10.1039/c9sc05066c},
url = {https://www.osti.gov/biblio/1816620},
journal = {Chemical Science},
issn = {ISSN 2041-6520},
number = {4},
volume = {11},
place = {United States},
publisher = {Royal Society of Chemistry},
year = {2019},
month = {12}}
USDOE Office of Science (SC), Basic Energy Sciences (BES). Scientific User Facilities Division; US Department of the Navy, Office of Naval Research (ONR); National Science Foundation (NSF)
Grant/Contract Number:
SC0012704
OSTI ID:
1816620
Journal Information:
Chemical Science, Journal Name: Chemical Science Journal Issue: 4 Vol. 11; ISSN 2041-6520