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Localized and Extended Exciton States in Solid C 60 Studied by Photoluminescence at High Pressure
Author(s) -
Meletov K. P.,
Negrii V. D.
Publication year - 1999
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/(sici)1521-3951(199901)211:1<217::aid-pssb217>3.0.co;2-3
Subject(s) - photoluminescence , exciton , redistribution (election) , spectral line , atomic physics , emission spectrum , condensed matter physics , chemistry , molecular physics , materials science , physics , optoelectronics , astronomy , politics , political science , law
We have measured the photoluminescence spectra of C 60 single crystals at T ≈ 10 K and pressures up to 4.0 GPa. The spectrum at normal pressure consists of a number of peaks, previously related to emission of localized Frenkel excitons. The pressure dependence of the spectrum shows a gradual red shift and a considerable redistribution of peak intensities. The intensities of almost all peaks decrease with increasing pressure, whereas one of them rapidly grows and dominates at P ≈ 1.7 GPa. The pressure‐induced shift of this peak is considerably higher than that of other peaks, and the pressure dependence of its position is strongly related to the pressure dependence of the direct gap. This peak may be associated with the vibronically assisted transition from the 1 T 1g extended exciton state.