ZnO nanostructure- and ZnO-Alq3 based thin layers for LED applications
Résumé
We present the ZnO (NPs) core-shell nanoparticles synthesised by the hydrolysis method [1-3] and the influence of various synthesis parameters on the morphological and optical properties of thin films containing these ZnO NPs characterized using Raman, SEM and spectroscopic methods. Their performance as white phosphors is then evaluated, through the measurements of their photoluminescent quantum yield. The synthesis of phosphors without rare earths is thus shown, allowing a better understanding of the role of the composition chemistry of the particles in their photoluminescence (PL) properties. Finally, the spectroscopic studies conducted permit to analyze the luminescence mechanisms occurring between core and the shell in NPs and more globally, in the mesospheres in which the NPs are organized within the thin layers. The possibility to apply them in white LEDs is also demonstrated.
Another family of ZnO-based materials which can be applied in LEDs are ZnO-Alq3 ((tris(8-hydroxyquinolinato)aluminium) in thin polymer layers. We present the optical properties of ZnO-Alq3 layers in various polymer matrices and propose the mechanisms which may be responsible for the PL emission in these materials.
References
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[2] Y. Zhang, A. Apostoluk, C. Theron, T. Cornier, B. Canut, S. Danièle, B. Masenelli, Sci. Rep. 9, 11959 (2019).
[3] Y. Zhang, T. Gard, C. Theron, A. Apostoluk, K. Masenelli-Varlot, B. Canut, S. Daniele, B. Masenelli, Applied Surface Science 540 (1), 148343 (2021).