| abstract |
Disclosed is a novel composition of matter that provides highly efficient energy conversion from NIR to NIR wavelengths, with either up-, down-, or both up- and down-converting transitions. Disclosed is a composition having the molecular formula NaYF4:YbxTmyNdz, where 0≤x≤0.98, 0≤y≤0.02, and 0≤z≤0.06. Also disclosed is a core-shell structure, wherein the core is a composition having the molecular formula NaYF4:YbxTmyNdz, where 0≤x≤0.98, 0≤y≤0.02, and 0≤z≤0.06, and the shell is composition having the molecular formula NaYF4:Ndw, where 0≤w≤0.1. |