Ultrafast dynamics of intersystem crossing and resonance energy transfer in Er(III)-quinolinolate complexes

Organocomplexes with trivalent erbium are investigated by time-resolved optical spectroscopy techniques. Ultrafast time scales are reported for intraligand intersystem crossing (similar to 10 ps) and ligand-to-metal resonance energy transfer (similar to 100 ps), resulting in lanthanide-ion sensitization with nearly unity efficiency. Given the interest of erbium complexes for telecom wavelength solid-state amplifiers and emitters, the results should stimulate further theoretical investigations on radiationless transitions in such complexes.