Titre :	Caractérisation structurale et optique des nanocristaux des semi-conducteurs Ga As et TiO2 inclus dans les monocristaux de KCL et de KBr
Type de document :	texte imprimé
Auteurs :	Nadia Berroual, Auteur ; M. Sebais, Directeur de thèse
Editeur :	Constantine : Université Mentouri Constantine
Année de publication :	2005
Importance :	74 f.
Format :	31 cm
Note générale :	2 copies imprimées disponibles
Langues :	Français (fre)
Tags :	Croissance cristalline  Absorption optique  Photoluminescence  Diffraction X  Nanocristaux  Semiconducteurs GaAs et TiO2 Nanocrystals  Semiconductors GaAs and TiO2  Crystal Growth  X Ray Diffraction  Optical Absorption  ??????????  ? ??? ? ??????? GaAs?  TiO2??? ?????  ??????  X?????? ????  ?????? ????
Index. décimale :	530 Physique
Résumé :	This work contains many and different results wich concerne elaboration and structural and optical carcterisationof nanocrystals of GaAs and TiO2 embedded in two different matrixes of alkali halides of KCl and KBr. The elaboration of the single crystals KCl and KBr was made bye pooling with Czochralski technique. The doping of these single crystals was realised during the growth of single crystals. Structural carcterisation with Xray diffraction, revealed the incorporation of nanocristallites of semiconductors GaAs and TiO2 in crystal matrixes. A caracterisation bye measurement of optical absorption in the range of UV-Visible (were KBr and KCl are transparant ) show a shift of the absorption edge of semiconductors GaAs and TiO2 to short long –waves ( so high energies) relatively to the absorption edge of large crystals of the same semiconductors. This shift is caused bye the size reduction effect, also of the edge shift, we can see on the absorption spectra, pics that was considered as excitonic pics. Nanocrystals size of GaAs and TiO2 semiconductors embedded in single crystals of KBr and KCl was estimated using the mass effective model as: In KBr R (GaAs) = 4.03 nm R(TiO2) = 2.73 nm In KCl R (GaAs) = 4.03 nm R(TiO2) = 3.22 nm A second optical caracterisation bye photoluminescence mesuerement show that the elaborated samples present luminescence bands in the visible range, wich can gave the possibility to considere theme as optical actif mediums.
Diplôme :	Magistère
En ligne :	../theses/physique/BER4355.pdf
Format de la ressource électronique :	pdf
Permalink :	https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=3331

Caractérisation structurale et optique des nanocristaux des semi-conducteurs Ga As et TiO2 inclus dans les monocristaux de KCL et de KBr [texte imprimé] / Nadia Berroual, Auteur ; M. Sebais, Directeur de thèse . - Constantine : Université Mentouri Constantine, 2005 . - 74 f. ; 31 cm.
2 copies imprimées disponibles
Langues : Français (fre)

Tags :	Croissance cristalline  Absorption optique  Photoluminescence  Diffraction X  Nanocristaux  Semiconducteurs GaAs et TiO2 Nanocrystals  Semiconductors GaAs and TiO2  Crystal Growth  X Ray Diffraction  Optical Absorption  ??????????  ? ??? ? ??????? GaAs?  TiO2??? ?????  ??????  X?????? ????  ?????? ????
Index. décimale :	530 Physique
Résumé :	This work contains many and different results wich concerne elaboration and structural and optical carcterisationof nanocrystals of GaAs and TiO2 embedded in two different matrixes of alkali halides of KCl and KBr. The elaboration of the single crystals KCl and KBr was made bye pooling with Czochralski technique. The doping of these single crystals was realised during the growth of single crystals. Structural carcterisation with Xray diffraction, revealed the incorporation of nanocristallites of semiconductors GaAs and TiO2 in crystal matrixes. A caracterisation bye measurement of optical absorption in the range of UV-Visible (were KBr and KCl are transparant ) show a shift of the absorption edge of semiconductors GaAs and TiO2 to short long –waves ( so high energies) relatively to the absorption edge of large crystals of the same semiconductors. This shift is caused bye the size reduction effect, also of the edge shift, we can see on the absorption spectra, pics that was considered as excitonic pics. Nanocrystals size of GaAs and TiO2 semiconductors embedded in single crystals of KBr and KCl was estimated using the mass effective model as: In KBr R (GaAs) = 4.03 nm R(TiO2) = 2.73 nm In KCl R (GaAs) = 4.03 nm R(TiO2) = 3.22 nm A second optical caracterisation bye photoluminescence mesuerement show that the elaborated samples present luminescence bands in the visible range, wich can gave the possibility to considere theme as optical actif mediums.
Diplôme :	Magistère
En ligne :	../theses/physique/BER4355.pdf
Format de la ressource électronique :	pdf
Permalink :	https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=3331