Please use this identifier to cite or link to this item: http://hdl.handle.net/123456789/3919
Title: Planarity and Length of the Bridge Control Rate and Efficiency of Intramolecular Singlet Fission in Pentacene Dimers
Authors: Paul, S
Govind, C
Karunakaran, V
Keywords: hydrocarbons
light absorption
aromatic compounds
absorption
oligomers
Issue Date: 14-Jan-2021
Publisher: American Chemical Society
Citation: The Journal of Physical Chemistry B; 125(1): 231-239
Abstract: Singlet fission (SF) improves the power conversion efficiency of optoelectronic devices by converting high-energy photons into two triplet excitons. SF dynamics and efficiency (Φ) are controlled by various factors. Here, the effect of planarity and length of the bridge in pentacene dimers on the intramolecular SF (iSF) process was investigated by synthesizing the dimers connected by bridges having fluorene (FL–PD, planar), methyl-substituted biphenyl (MBP–PD, twisted), and diphenyl acetylene (DPA–PD, longer) groups and characterizing their excited-state relaxation dynamics using nanosecond and femtosecond pump–probe spectroscopy. Transient absorption studies reveal that iSF dynamics of FL–PD having a planar bridge are ∼787 times faster (187 ps) and exhibit higher Φ (198%) by feasible electronic coupling, compared to MBP–PD possessing a twisted bridge showing a low Φ of ∼16%. However compared to FL–PD, iSF dynamics of DPA–PD with an increase of bridge length are slower by an order (1.09 ns) and show comparable Φ of 185% through extended conjugation. Thus, the planarity and length of the bridge in pentacene dimers control the rate and efficiency of the iSF process.
URI: https://pubs.acs.org/doi/10.1021/acs.jpcb.0c08590
http://hdl.handle.net/123456789/3919
Appears in Collections:2021



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