Strategies for the design of luminescent lanthanide(III) complexes and their photonic applications

Strategies for the design of luminescent lanthanide complexes, especially Nd(III) complexes are introduced in this review. The relatively low efficiency of Nd(III) emission in solution has been attributed to: (1) the radiationless transition process via vibrational excitation of the surrounding medium; (2) dipole–dipole non-radiative energy transfer processes via cross-relaxation and excitation migration; and (3) characteristics of perturbation of Nd(III) f orbitals by the surrounding environment. A Nd(III)-doped organic medium could be used as a strong luminescent material if these contributions could be controlled via the design of ligands for the Nd(III) complexes. Furthermore, recent photonic applications using Nd(III), Eu(III) and Tb(III) complexes are demonstrated in this paper. The design of lanthanide(III) complexes and luminescence-based applications, including the fabrication of devices, are expected to open up pioneering fields in materials science.