Charge transfer excited states sensitization of lanthanide emitting from the visible to the near-infra-red

Since the pioneering studies of Weissman in the 1940s, the sensitization of lanthanide luminescence via the antenna effect is becoming extremely classical. The photophysical sensitization process generally involves an energy transfer from the triplet excited state of an organic or a transition metal containing an antenna chromophore. Recently, the direct lanthanide sensitization from charge transfer excited state appears as an alternative process resulting in a red-shift of the excitation wavelength far in the visible thanks to the design of ligands with appropriate donor–acceptor charge transfer transitions. This review presents the research endeavor in this area and underlines related applications in nonlinear optics.