Abstract: Due to low toxicity, high stability and high photoluminescence, lanthanide doped upconversion nanoparticles has a promising appliment in bioimaging and boilable. Here, monodispersed and uniform NaMn3 F10∶Yb/( Er,Tm,Ho) nanoparticles were synthesized by common thermal decomposited method. The sizes of all synthesized nanoparticles were lower than 10 nm. It was found that the NaMn3 F10∶Yb/Er NaMn3 F10∶Yb/Tm radiated single 660 nm and 800 nm under the excitation of 980 nm continue wave laser, respectively. It mainly attribute to the act of the 4 T1 level of Mn2+ ions, which could act as the intermediate energy and facilitate the non-radiative energy transfer from the 2 H11/2 and 4 S3/2 levels to the 2 F9/2 level of Er3+ ions so that the intensity of 2 F9/2 level ( red emission) were enhanced and the intensity of 2 H11/2 and 4 S3/2 levels ( green emission) were suppressed. Finally, it was found by incorporating the Mn2+ ions into NaYF4 nanoparticles that the emission color and red/green ratio were enhanced gradually as imcreasing the Mn2+ concentration. The nanoparticles with pure red emission were obtained when the Mn2+ ions comcentration was up to 58;.

Key words: Due to low toxicity, high stability and high photoluminescence, lanthanide doped upconversion nanoparticles has a promising appliment in bioimaging and boilable. Here, monodispersed and uniform NaMn3 F10∶Yb/( Er,Tm,Ho) nanoparticles were synthesized by common thermal decomposited method. The sizes of all synthesized nanoparticles were lower than 10 nm. It was found that the NaMn3 F10∶Yb/Er NaMn3 F10∶Yb/Tm radiated single 660 nm and 800 nm under the excitation of 980 nm continue wave laser, respectively. It mainly attribute to the act of the 4 T1 level of Mn2+ ions, which could act as the intermediate energy and facilitate the non-radiative energy transfer from the 2 H11/2 and 4 S3/2 levels to the 2 F9/2 level of Er3+ ions so that the intensity of 2 F9/2 level ( red emission) were enhanced and the intensity of 2 H11/2 and 4 S3/2 levels ( green emission) were suppressed. Finally, it was found by incorporating the Mn2+ ions into NaYF4 nanoparticles that the emission color and red/green ratio were enhanced gradually as imcreasing the Mn2+ concentration. The nanoparticles with pure red emission were obtained when the Mn2+ ions comcentration was up to 58;.