9 February 1995 Nonradiative branching processes of self-trapped excitons in cadmium halide crystals
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Proceedings Volume 2362, International Conference on Excitonic Processes in Condensed Matter; (1995) https://doi.org/10.1117/12.200961
Event: Excitonic Processes in Condensed Matter: International Conference, 1994, Darwin, Australia
Abstract
Temperature dependence of luminescence spectra, intensity and life-time has been measured precisely in CdBr2 to investigate whole decay kinetics of self-trapped excitons (STE's). Below 50 K, a near-ultraviolet (UV) emission band appears at 3.3 eV. The initial state for the UV-emission consists of spin singlet and triplet states. The ratio of population branching of the optically created excitons into singlet to triplet was observed as 6:94. The triplet state further split into closely lying three levels. From analysis on the decay components, the ratio among initial populations of these levels was determined as 1:6:0 in order from lower to higher levels. Above 50 K, the intensity of the UV-emission decreases rather rapidly. About half of the STE's in the UV-state are transferred into another STE state responsible for yellow (Y) emission at 2.2 eV. Another half of STE's decay directly into ground state non-radiatively. The Y-state comprise two kinds of states, each of which further split into two states. Two pairs of decay components, namely four components, were observed between 50 and 150 K. Temperature dependence of time-integrated intensity was determined for each decay component. Above 150 K, all STE's are to be de-excited non-radiatively through thermal processes.
© (1995) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Hideyuki Nakagawa, Hideyuki Nakagawa, Mamoru Kitaura, Mamoru Kitaura, } "Nonradiative branching processes of self-trapped excitons in cadmium halide crystals", Proc. SPIE 2362, International Conference on Excitonic Processes in Condensed Matter, (9 February 1995); doi: 10.1117/12.200961; https://doi.org/10.1117/12.200961
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