Second-order photochemical upconversion in organic systems.
In order to extend the photon energy shift of sensitized upconversion processes based on triplet-triplet annihilation in multicomponent organic systems, we have demonstrated that it is possible to exploit a sequence of consecutive upconversion steps. We have therefore realized an all-optical device for double upconversion: a light blue-shift of more than 0.9 eV was obtained at an excitation irradiance of a few tens of milliwatts per square centimeter.
Dipartimento di Scienza dei Materiali, Università Milano Bicocca , via R. Cozzi 55, 20125 Milano, Italy.
Angelo
A
Monguzzi
Francesco
F
Meinardi