Sol-gel transparent nano-glass-ceramics comprising rare-earth-doped NaYF4nanocrystals

✍ Scribed by Santana-Alonso, A. ;Yanes, A. C. ;Méndez-Ramos, J. ;del-Castillo, J. ;Rodríguez, V. D.

• Book ID: 105365352
• Publisher: John Wiley and Sons
• Year: 2009
• Tongue: English
• Weight: 620 KB
• Volume: 206
• Category: Article
• ISSN: 0031-8965
• DOI: 10.1002/pssa.200881717

✦ Synopsis

Abstract

Transparent nano‐glass‐ceramics containing rare‐earth‐doped NaYF~4~ nanocrystals (Eu^3+^ single‐doped and Yb^3+^–Er^3+^ co‐doped) have been successfully developed for the first time by thermal treatment of precursor bulk glasses obtained by sol–gel technique. X‐ray diffraction and high‐resolution transmission electron microscopy measurements reveal the precipitation of NaYF~4~ nanocrystals during the heat treatment and their corresponding sizes have been calculated. Luminescence measurements confirm the partition of rare‐earth ions in NaYF~4~ nanocrystals. In Eu^3+^‐doped samples, changes in the local environment of these rare‐earth ions have been investigated by site‐selective emission and excitation spectra. In Yb^3+^–Er^3+^ co‐doped samples, efficient visible up‐conversion luminescence has been obtained under infrared excitation at 980 nm. The red to green up‐conversion emission ratio can be varied as a function of temperature of heat treatment, resulting in colour tuneable up‐conversion phosphors with applications in optical integrated devices. Colour tuneability has been analysed and quantified in terms of Comission Internationale d'Eclairage standard chromaticity diagram.

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