Vibrational energy dependence of the triplet lifetime in isolated, photoexcited C60

被引:5
作者
Echt, O [1 ]
Yao, SN
Deng, RP
Hansen, K
机构
[1] Univ New Hampshire, Dept Phys, Durham, NH 03824 USA
[2] Univ Gothenburg, Dept Expt Phys, SE-41296 Gothenburg, Sweden
关键词
D O I
10.1021/jp048313u
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
We have measured the lifetime tau of the lowest triplet state T-1 in free C-60 by a pump-probe experiment using lasers with nanosecond pulse durations. At low pump fluence the population of T-1 decays with a distinct, narrow distribution of lifetimes. tau depends on the pump wavelength ( lambda = 532, 355, or 266 nm) as well as the temperature of the source from which C-60 is vaporized (420 less than or equal to T less than or equal to 510degreesC); it ranges from 2 mus to 0.3 mus. At high pump fluence an additional lifetime as short as 40 ns is observed. A consistent correlation of all observed lifetimes with the experimental parameters is found if tau is assigned to an ensemble Of C-60 (T-1) that has absorbed either one or two pump photons with the excess energy being randomized over all vibrational modes. Thus, tau = 2 mus corresponds to a vibrational energy E-vib = E-total E-triplet = 4.6 eV (one-photon absorption at A = 532 nm, T = 420degreesC) while tau = 40 ns corresponds to Evib 9.6 eV (two-photon absorption at 355 nm, 480 degreesC). This result strongly suggests that delayed electrons that are emitted from highly excited C-60 (E-vib much greater than 10 eV) on the time scale of approximate to10 ns to 1 ms are not affected by long-lived electronically excited states. The frequently questioned description of delayed electron emission from photoexcited C60 as thermionic emission is, therefore, warranted.
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页码:6944 / 6952
页数:9
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共 55 条
  • [1] Excitation of Rydberg series in C60 -: art. no. 273401
    Boyle, M
    Hoffmann, K
    Schulz, CP
    Hertel, IV
    Levine, RD
    Campbell, EEB
    [J]. PHYSICAL REVIEW LETTERS, 2001, 87 (27) : 273401 - 273401
  • [2] COLLISION-INDUCED FRAGMENTATION OF SMALL (CO2)N(+) CLUSTERS
    CAMPBELL, EEB
    TITTES, A
    KRANTZ, D
    SCHNEIDER, R
    HIELSCHER, A
    [J]. CHEMICAL PHYSICS LETTERS, 1991, 184 (5-6) : 404 - 410
  • [3] The transition from direct to delayed ionisation of C60
    Campbell, EEB
    Hoffmann, K
    Hertel, IV
    [J]. EUROPEAN PHYSICAL JOURNAL D, 2001, 16 (1-3) : 345 - 348
  • [4] Fullerene reactions
    Campbell, EEB
    Rohmund, F
    [J]. REPORTS ON PROGRESS IN PHYSICS, 2000, 63 (07) : 1061 - 1109
  • [5] THERMIONIC EMISSION FROM THE FULLERENES
    CAMPBELL, EEB
    ULMER, G
    HERTEL, IV
    [J]. ZEITSCHRIFT FUR PHYSIK D-ATOMS MOLECULES AND CLUSTERS, 1992, 24 (01): : 81 - 85
  • [6] Delayed ionization and fragmentation en route to thermionic emission: Statistics and dynamics
    Campbell, EEB
    Levine, RD
    [J]. ANNUAL REVIEW OF PHYSICAL CHEMISTRY, 2000, 51 : 65 - 98
  • [7] Hyperthermal collisions of atomic clusters and fullerenes
    Deng, R
    Echt, O
    [J]. INTERNATIONAL JOURNAL OF MASS SPECTROMETRY, 2004, 233 (1-3) : 1 - 12
  • [8] On the triplet lifetime in free, photo-excited C60
    Deng, R
    Treat, M
    Echt, O
    Hansen, K
    [J]. JOURNAL OF CHEMICAL PHYSICS, 2003, 118 (19) : 8563 - 8565
  • [9] Efficiency of thermionic emission from C60
    Deng, RP
    Echt, O
    [J]. JOURNAL OF PHYSICAL CHEMISTRY A, 1998, 102 (15) : 2533 - 2539
  • [10] MULTIPHOTON IONIZATION OF C60
    DING, D
    COMPTON, RN
    HAUFLER, RE
    KLOTS, CE
    [J]. JOURNAL OF PHYSICAL CHEMISTRY, 1993, 97 (11) : 2500 - 2504