Journal of Physical Chemistry A, Vol.118, No.8, 1439-1442, 2014
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.