Upconversion in molecular hetero-nonanuclear lanthanide complexes in solution

Here we show that nonanuclear lanthanide complexes respresent a new class of solution state upconversion (UC) molecules. For a composition of one Tb per eight Yb the nonanuclear complexes display a very efficient UC phenomenon with Tb luminescence in the visible region upon 980 nm NIR excitation of Yb. An unprecedented value of 1.0 x 10(-7) was obtained for the UC efficiency at only 2.86 W cm(-2), demonstrating these new molecular complexes to be up to 26 times more efficient than the best current molecular systems, the UC being observed down to a concentration of 10 nM.

Automated summary

Nonanuclear lanthanide complexes represent a new class of solution-state upconversion (UC) molecules, showing a very efficient UC phenomenon with Tb luminescence in the visible region upon 980 nm NIR excitation of Yb. These new molecular complexes exhibit an unprecedented UC efficiency of 1.0 x 10(-7) at only 2.86 W cm(-2), up to 26 times more efficient than current molecular systems, and UC can be observed down to a concentration of 10 nM.