Abstract
Data presented on the influence of the temperature in the range 80-650 K on the spectral kinetics of the luminescence and transient absorption of unactivated CsI crystals under irradiation by pulsed electron beams (〈E〉 = 0.25 MeV, t1/2 = 15 ns, j = 20 A/cm2). The structure of the short-wavelength part of the transient absorption spectra at T = 80- 350 K exhibits features, suggesting that the nuclear subsystem of self-trapped excitons (STE's) transforms repeatedly during their lifetime until their radiative annihilation at T≥ 80 K, alternately occupying di- and trihalide ionic configurations. It is established that a temperature-induced increase in the yield of radiation defects, as well as F and H color centers, and quenching of the UV luminescence in CsI occur in the same temperature region (above 350 K) and are characterized by identical thermal activation energies (∼0.22 eV). It is postulated that the STE's in a CsI crystal can have a trihalide ionic core with either an on-center or off-center configuration; the high-temperature luminescence of CsI crystals is associated with the radiative annihilation of an off-center STE with the structure (I-(I0I- e-))*.
Original language | English |
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Pages (from-to) | 586-590 |
Number of pages | 5 |
Journal | Physics of the Solid State |
Volume | 40 |
Issue number | 4 |
Publication status | Published - Apr 1998 |
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics