. Afin-de-pouvoir-comparer-l, évolution relative des différentes bandes de luminescence avec le pourcentage d'alumine ?*, les spectres ont été pondérés pour que la bande verte (530 nm) ait la même intensité pour chacun des spectres. Cela permet de tenir compte aussi de la quantité de matière sondée qui n'est jamais parfaitement identique d'une expérience à l'autre. Le signal de la poudre contenant encore de l'aluminium (spectre noir) est moins intense que les autres, les pics dus à la source excitatrice (marqués d'une étoile) sont encore visibles

A. Partir-de-l-'étude-microstructurale, Sa morphologie et sa localisation au niveau du « volcan » laisse supposer qu'il serait composé d'alumine ?*. L'agglomérat de particules est vraisemblablement constitué de particules d'alumines ?, ?*, ?, et de nitrure d'aluminium intimement imbriquées les unes dans les autres. Il n'est pas possible de les distinguer. Les spectres de cathodoluminescence correspondant à l'émission des nanofils n'ont pu être mesurés sur toute la gamme spectrale du détecteur (220 à 920 nm) en une seule prise de mesure. En effet les nanofils les plus fins se dégradaient sous le faisceau, certains d'entre eux ont même été coupés en deux, De plus les effets de charge entraînent un déplacement du nanofil et

. Fig, 7 : Spectres de cathodoluminescence du nanofil marqué d'un cercle (figure 5.6.a) et d'une particule semblable à celle marquée d'une croix

. Elle-proviendrait-d, une recombinaison tunnel d'un électron d'un niveau donneur (lacune en oxygène V O ) avec un trou d'un niveau accepteur (lacune de gallium V Ga ou lacune d'une paire chargée de lacune gallium et oxygène (V Ga , V O )') [15-16, Cette bande bleue est aussi observée dans le cas d'impuretés (Zn 4+ , Si 4+ )

S. Ge, D. P. Pourtant, and . Yu, 16] font la remarque que selon les conditions d'élaboration, la luminescence de l'oxyde de gallium peut être soit située dans le vert soit localisée dans le bleu

. Inversement, plus le milieu est oxydant, plus la luminescence est intense et déplacée vers le vert

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