Solvothermal synthesis and luminescence properties of NaYF4:Ln3+ (Eu3+, Tb3+, Yb3+/Er3+) nano- and microstructures
摘要
NaYF4 and NaYF4 (Eu3+, Tb3+, Yb3+/Er3+) nano- and microstructures were successfully synthesized through a facile and effective polyol-mediated route with ethylene glycol (EG) as solvent. The factors including the molar ratio of F鈭?/sup>/Y3+, reaction temperature and reaction time were well studied in the influences on size, morphology and phase transition of samples. The experimental results indicate that the F鈭?/sup>/Y3+ ratio and reaction temperature play key roles in crystal phase and morphology of the product. Higher molar ratio of F鈭?/sup>/Y3+ and higher temperature as well as longer reaction time facilitate 伪 cubic structure-to-尾 hexagonal structure phase transition, which behaves as a dissolution-recrystallization transformation process. Photoluminescence measurements demonstrated that the as-prepared 尾-NaYF4 is one good up- and down-conversion luminescent host material.