Branch-shaped NaGdF4:Eu3+ nanocrystals: Selective synthesis, and photoluminescence properties

作者：Wang Shang Bing^*; Li Qing; Pei Li Zhai; Zhang Qian Feng

来源：Materials Characterization, 2010, 61(8): 824-830.

DOI：10.1016/j.matchar.2010.04.015

• NaGdF4:Eu3+ nanocrystals
• Phase-controlled synthesis
• Photoluminescence

The branch-shaped NaGdF4:Eu3+ nanocrystals (NCs) were synthesized by using polyvinylpyrrolidone (PVP) as a capping agent in ethylene glycol (EG) solution. The NCs were readily dispersed into water or ethanol to form a relatively stable suspension, which may facilitate their applications in biological fields. Meanwhile, the crystal structures of the NCs were tunable from the mixture of the alpha-(cubic) and beta-(hexagonal) phases to the pure beta-phase by varying the F-/Ln(3+) molar ratio or the reaction temperature. The pure beta-phase NCs were obtained at relatively high F-/Ln(3+) molar ratio and reaction temperature. In addition, the Eu3+-doping concentration-dependent optical properties of the NaGdF4:Eu3+ NCs were investigated in detail. The result shows that the emissions from high energy level transitions (e.g., D-5(1), D-5(2), and D-5(3)) are significantly impaired with increasing the Eu3+-doping concentration due to the cross-relaxation process, and the emission at 612 nm is predominant since the doped Eu3+ ions locate in the crystal fields without inversion center.

• 出版日期2010-8
• 单位安徽工业大学