pH value manipulated phase transition, microstructure evolution and tunable upconversion luminescence in Yb super(3+)-Er super(3+) codoped LiYF sub(4)/YF sub(3) nanoparticles

• Published in: Dalton transactions : an international journal of inorganic chemistry Vol. 44; no. 35; pp. 15583 - 15590
• Main Authors: Ye, Song, Hu, Rongxuan, Jiang, Nan, Wang, Huiyun, Wang, Deping
• Format: Journal Article
• Language: English
• Published: 01.08.2015
• Subjects: Emission spectroscopy; Microstructure; Nanocrystals; Nanoparticles; Rare earth metals; Synthesis; Upconversion
• ISSN: 1477-9226; 1477-9234
• DOI: 10.1039/c5dt01552a

The pH value plays an important role in controlling the crystallization process and microstructure of the final products in the synthesis of nanocrystals with a solvothermal method. This work reported the effect of the mother solution pH value on the precipitation of LiYF sub(4) and YF sub(3) nanoparticles, as well as the microstructure evaluation of YF sub(3) from a bowknot-like to spindle-like shape. Spectroscopy study suggests that there is strong correlation between the upconversion emission properties of the Yb super(3+)-Er super(3+) couple and the phase and the microstructure of the host. The strongest emissions and lowest red-to-green ratio are observed in the bowknot-like YF sub(3) nanocrystals with the largest open ends. Further spectral investigation indicates that the phase and microstructure dependent upconversion properties are associated with the upconversion efficiency. The present study is of great importance in the design and synthesis of rare earth ion doped nanocrystals with tunable upconversion properties.