Non-coherent low-power up-conversion in multicomponent organic systems

(ricevuto il 24 Febbraio 2010; revisionato il 16 Marzo 2010; approvato il 27 Aprile 2010; pubbli-cato online il 21 Maggio 2010)Summary. — A new route to realize photon up-conversion is presented, based onharnessing energy through bimolecular processes involving triplet-triplet annihila-tion sensitized via resonant energy transfer. The process is inherently independentof the coherence of the incoming photons, and, thanks to the large population ofmetastable triplet states given by the transfer, up-converted photons can be ob-tained by using ultra low excitation power densities similar to the solar emissionlevel.PACS 33.50.-j – Fluorescence and phosphorescence; radiationless transitions,quenching (intersystem crossing, internal conversion).PACS 42.79.Nv – Optical frequency converters.PACS 33.80.-b – Photon interactions with molecules.