| Autor: |
G. A. Machintsev, D. L. Fedorov, L. S. Markov, P. V. Shapkin, Yurii V Korostelin, Alexander S. Nasibov |
| Rok vydání: |
1991 |
| Předmět: |
|
| Zdroj: |
SPIE Proceedings. |
| ISSN: |
0277-786X |
| DOI: |
10.1117/12.24314 |
| Popis: |
Complex spectroscopical and piezospectroscopical investigations of system ZnCdi-Se used in laser cathode-ray devices were realised in the whole composition range 1 . Westudied the luminescence features connected with excitons localized by potential fluctuations caused by both compositional and structural disorder and also the influence of elastic stresses on the properties of the laser screen. Solid solutions of semiconductors are weakly disordered systems in which the disorder involves composition fluctuations and therefore crystal potential field fluctuations. In ideal solutions of this kind the arrangement of the substituent atoms at sites of the relevant sublattice is a random one. They include ternary direct-gap Il-VT materials based on zinc and cadmium chalcogenides with substitution in the cationic sublattice. These systems can exist with any ratio of the components and their electronic properties (band gap valence band splitting energy) vary smoothly with the composition. For 11-VT materials where the excitonic states have large radii(a 3- lOnm) the most probable interaction is whith large-scale composition fluctuations having dimension R a . A theoretical treatment 2 shows that such an interaction causes both localization of excitons by large-scale composition fluctuations forming a density tail of localized excitonic states in the band gap which create the long-wavelength part of the absorption line and scattering of delocalized excitonic states which create the short- wavelength part of the absorption line. The fluctuational disorder causes a composition dependent broadening of the |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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