Bartram, RH;
Stoneham, AM;
(1975)
On the luminescence and absence of luminescence of F centers.
Solid State Communications
, 17
(12)
1593 - 1598.
10.1016/0038-1098(75)91003-0.
Preview |
PDF
59741.pdf Download (498kB) |
Abstract
A model, proposed originally by Dexter, Klick and Russell, is used to explain the occurence or non-occurence of F-center luminescence in ionic crystals, in terms of a simple two-state configuration coordinate diagram. In this model, which works for all known cases, luminescence is quenched by a competing non-radiative process whenever the intersection of the ground and excited state curves lies below the energy reached in absorption in a vertical (Franck-Condon) transition. The criterion for the occurence of luminescence is expressed as Λ < 1/4 , where Λ (=excited-state lattice-relaxation energy/optical-absorption energy) is a parameter, related to the relative displacement of the two curves, which can be inferred from data on the temperature dependence of the F-band line width. Thus the possibility of observing luminescence can be predicted from optical absorption data alone. It is found emperically that Λ for alkali halides with rocksalt structure is independent of lattice parameter, and the observed dependence of Λ on the ratio of ionic radii in terms of ion-size effects. Values of Λ range from 0.009 for CsF to 0.831 for LiI; NaCl with Λ = 0.260 is a marginal case for luminescence.
Type: | Article |
---|---|
Title: | On the luminescence and absence of luminescence of F centers |
Open access status: | An open access version is available from UCL Discovery |
DOI: | 10.1016/0038-1098(75)91003-0 |
Publisher version: | http://dx.doi.org/10.1016/0038-1098(75)91003-0 |
Language: | English |
Additional information: | Text made available to UCL Discovery by kind permission of Elsevier, 2012 |
UCL classification: | UCL UCL > Provost and Vice Provost Offices UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences |
URI: | https://discovery.ucl.ac.uk/id/eprint/59741 |
Archive Staff Only
View Item |