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Title: Comparative study of exciton relaxation dynamics in C{sub 60} and C{sub 70} solid

Abstract

The exciton dynamics of C{sub 70} solid has been investigated by the time-resolved photoluminescence (PL) and transient absorption (TA) technique and compared with the case of C{sub 60} solid. Three distinct PL bands were observed at 685, 715, and 740 nm. The high-energy band at 685 nm displayed an almost purely single-exponential decay profile, while the other two exhibited a slow-decaying tail as well, especially at low temperatures. Laser fluence dependence of PL decay profiles shows that the decay in C{sub 70} solid, in contrast to the case of C{sub 60}, is predominantly governed by fast (20 ps) nonradiative exciton-trap annihilation, with the intersystem crossing playing a minor role in lower energy bands at 715 and 740 nm. On the other hand, laser fluence dependence of transient absorption signals shows that the decay in C{sub 70} is much faster than PL decay, which indicates the fast component arises from the exciton-exciton annihilation process under extremely high laser fluence condition.

Authors:
; ;  [1]; ;  [2]
  1. Seoul National Univ. (Korea, Republic of). Dept. of Chemistry
  2. Korea Research Inst. of Standards and Science, Taejon (Korea, Republic of)
Publication Date:
OSTI Identifier:
682069
Resource Type:
Journal Article
Journal Name:
Journal of Physical Chemistry B: Materials, Surfaces, Interfaces, amp Biophysical
Additional Journal Information:
Journal Volume: 103; Journal Issue: 31; Other Information: PBD: 5 Aug 1999
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 40 CHEMISTRY; EXCITONS; RELAXATION; FULLERENES; PHOTOLUMINESCENCE; DYNAMICS; LASERS

Citation Formats

Cho, H.S., Yang, S.I., Kim, S.K., Shin, E., and Kim, D. Comparative study of exciton relaxation dynamics in C{sub 60} and C{sub 70} solid. United States: N. p., 1999. Web. doi:10.1021/jp991252t.
Cho, H.S., Yang, S.I., Kim, S.K., Shin, E., & Kim, D. Comparative study of exciton relaxation dynamics in C{sub 60} and C{sub 70} solid. United States. doi:10.1021/jp991252t.
Cho, H.S., Yang, S.I., Kim, S.K., Shin, E., and Kim, D. Thu . "Comparative study of exciton relaxation dynamics in C{sub 60} and C{sub 70} solid". United States. doi:10.1021/jp991252t.
@article{osti_682069,
title = {Comparative study of exciton relaxation dynamics in C{sub 60} and C{sub 70} solid},
author = {Cho, H.S. and Yang, S.I. and Kim, S.K. and Shin, E. and Kim, D.},
abstractNote = {The exciton dynamics of C{sub 70} solid has been investigated by the time-resolved photoluminescence (PL) and transient absorption (TA) technique and compared with the case of C{sub 60} solid. Three distinct PL bands were observed at 685, 715, and 740 nm. The high-energy band at 685 nm displayed an almost purely single-exponential decay profile, while the other two exhibited a slow-decaying tail as well, especially at low temperatures. Laser fluence dependence of PL decay profiles shows that the decay in C{sub 70} solid, in contrast to the case of C{sub 60}, is predominantly governed by fast (20 ps) nonradiative exciton-trap annihilation, with the intersystem crossing playing a minor role in lower energy bands at 715 and 740 nm. On the other hand, laser fluence dependence of transient absorption signals shows that the decay in C{sub 70} is much faster than PL decay, which indicates the fast component arises from the exciton-exciton annihilation process under extremely high laser fluence condition.},
doi = {10.1021/jp991252t},
journal = {Journal of Physical Chemistry B: Materials, Surfaces, Interfaces, amp Biophysical},
number = 31,
volume = 103,
place = {United States},
year = {1999},
month = {8}
}