SELF-TRAPPED EXCITONS AND INTERSTITIAL VACANCY PAIRS IN OXIDES.
PHILOS MAG B
955 - 964.
Experimental data on the temperature dependence of the lifetimes of transient luminescence, optical absorption, and volume change, associated with self-trapped excitons (STEs), as well as the observed optical conversion from defect pairs (DPs) to STEs, have inspired two recent theoretical studies aimed at STEs and DPs in SiO2. One is a quantum-mechanical reaction-rate processing of the lifetime versus temperature data, while the other is a quantum-chemical study of excitons and DPs, both aiming at revealing the character of the STE and DP structures, as well as of the adiabatic potential energy surfaces (APESs) and ionic displacements resulting in the STE-to-DP interconversion. Both theoretical approaches are found to lead to convergent conclusions which are now summarized and discussed from a unified viewpoint. It is shown that qualitative characteristics of the APES of the lowest excited state of SiO2 can also be related to a wider class of compounds with highly ionic and mixed ionic-covalent bond character.
|Title:||SELF-TRAPPED EXCITONS AND INTERSTITIAL VACANCY PAIRS IN OXIDES|
|Keywords:||TRANSIENT OPTICAL-ABSORPTION, ELECTRONIC EXCITATION, LATTICE-DEFECTS, CRYSTALLINE SIO2, HALIDE CRYSTALS, AMORPHOUS SIO2, LUMINESCENCE, CREATION, CENTERS, PHOTOGENERATION|
|UCL classification:||UCL > School of BEAMS
UCL > School of BEAMS > Faculty of Maths and Physical Sciences
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