Photon Upconversion in a Molecular Lanthanide Complex in Anhydrous Solution at Room Temperature

Abstract

Molecular photon upconversion luminescence was observed from an ion-associated complex of an erbium chelate of 2-thenoyltrifluoroacetone and a near-infrared-emitting cyanine dye in anhydrous solution at room temperature. In the complex erbium was sensitized by the organic antenna dye excited at 808 nm. The result was characteristic erbium emission at 510–565 nm with second-order dependence on the excitation power, suggesting a dye-sensitized energy transfer upconversion mechanism. Compared to inorganic upconverting nanoparticles, the organic molecular dye-sensitized complexes are expected to offer higher molar absorptivity, smaller well-defined size, and simpler addition of functional groups.