TY - JOUR
T1 - Femtosecond to nanosecond dynamics in fullerenes
T2 - Implications for excitedstate optical nonlinearities
AU - Klimov, Victor I
AU - Smilowitz, L.
AU - Wang, H.
AU - Grigorova, M.
AU - Robinson, J. M.
AU - Koskelo, A.
AU - Mattes, B. R.
AU - Wudl, F.
AU - McBranch, D. W.
PY - 1997/7
Y1 - 1997/7
N2 - We compared detailed dynamics of the excited-state absorption for C60 in solution, thin films, and entrapped in an inorganic sol-gel glass matrix. Our results demonstrate that the microscopic morphology of the C60 molecules plays a crucial role in determining the relaxation dynamics. This is a key factor for applications in optical limiting for nanosecond pulses using reverse saturable absorption. We find that the dynamics of our C60-glass composites occur on long (ns) timescales, comparable to those in solution; thin film samples, by contrast, show rapid decay (60-sol-gel glass composites contain C60 in a molecular dispersion, and are suitable candidates for solid-state optical limiting. Multispectral analysis of the decay dynamics in solution allows accurate determination of both the intersystem crossing time (600±100ps) and the relative strengths of the singlet and triplet excited-state cross sections as a function of wavelength from 450-950 nm. The triplet excited-state cross section is greater than that for the singlet excited-state over the range from 620-810 nm.
AB - We compared detailed dynamics of the excited-state absorption for C60 in solution, thin films, and entrapped in an inorganic sol-gel glass matrix. Our results demonstrate that the microscopic morphology of the C60 molecules plays a crucial role in determining the relaxation dynamics. This is a key factor for applications in optical limiting for nanosecond pulses using reverse saturable absorption. We find that the dynamics of our C60-glass composites occur on long (ns) timescales, comparable to those in solution; thin film samples, by contrast, show rapid decay (60-sol-gel glass composites contain C60 in a molecular dispersion, and are suitable candidates for solid-state optical limiting. Multispectral analysis of the decay dynamics in solution allows accurate determination of both the intersystem crossing time (600±100ps) and the relative strengths of the singlet and triplet excited-state cross sections as a function of wavelength from 450-950 nm. The triplet excited-state cross section is greater than that for the singlet excited-state over the range from 620-810 nm.
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U2 - 10.1163/156856797X00024
DO - 10.1163/156856797X00024
M3 - Article
AN - SCOPUS:0000561047
VL - 23
SP - 587
EP - 600
JO - Research on Chemical Intermediates
JF - Research on Chemical Intermediates
SN - 0922-6168
IS - 7
ER -