文摘
UCNPs (GdF3, YF3, NaGdF4 and NaYF4) co-doped by Yb3+/Tm3+ had been synthesized at 150 °C. The growth process and upconversion mechanism of UCNPs had been deduced by schematic diagram. The accumulation and energy transfer of Gd3+ could be demonstrated in the polycrystalline host.