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Dissipation dynamics of intrachain exciton coupled with phonons in MEH‐PPV: Time‐resolved multiplex coherent anti‐Stokes Raman scattering
Author(s) -
Wang Jiao,
Wang Quan,
Wang Wenyan,
Wang Lin,
Kang Zhihui,
Yang Yanqiang,
Zhang Hanzhuang,
Wang Yinghui
Publication year - 2019
Publication title -
journal of raman spectroscopy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.748
H-Index - 110
eISSN - 1097-4555
pISSN - 0377-0486
DOI - 10.1002/jrs.5544
Subject(s) - phonon , exciton , raman spectroscopy , raman scattering , coherent spectroscopy , spectroscopy , relaxation (psychology) , coherent anti stokes raman spectroscopy , molecular physics , dissipation , condensed matter physics , materials science , chemistry , chemical physics , physics , optics , quantum mechanics , psychology , social psychology
Abstract Time‐resolved coherent anti‐Stokes Raman spectroscopy can disentangle the exciton energy dissipation (EED) dynamics of the intrachain exciton in conjugated polymers (MEH‐PPV) coupled with several phonon modes and the corresponding phonon relaxation dynamics by adjusting the timing between lasers in the coherent anti‐Stokes Raman spectroscopy system. The intrachain EED process is coupled with phonon modes located at 966; 1118; 1283; and 1560 cm −1 , respectively. Of these, the phonon mode at 966 cm −1 corresponds to the out‐of‐plane CH bending vibration in the vinylene group. This is the primary channel for EED because the vinylene group is close to the conjugated unit and the corresponding chemical bond is flexible. After annihilation of the intrachain exciton, some excess energy from MEH‐PPV in the ground state would further dissipate via energy redistribution between phonon modes at 1283 and 1118 cm −1 , ultimately leading to phonon relaxation.