Kinetic selection of nonradiative excitation in photonic nanoparticles Gd2O3:Er
In the present work, we separate and classify four different pathways for UV-vis energy conversion with participation of Gd3+def and Er3+ ions located at dissimilar structural sites in the Gd2O3 lattice. The Gd3+def centers represent host cations with a distorted environment due to the nearest defects of the anionic sublattice. Two non-equivalent types of both Gd3+def donor and Er3+ acceptor centers occupying C2 and S6 structural sites are selected in Gd2O3:Er nanoparticles by the spectral-kinetic method. Such structural features provide the realization of several parallel channels of nonradiative Gd3+def → Er3+ energy migration and lead to a multimodal distribution of emission centers over the lifetime of the Er3+ excited states. The widths and the maxima of the kinetic parameter distributions depend on the degree of disorder in the nearest environment of Gd3+def donor centers. Our data show the possibility of practical realization of what is regarded as an additional pathway for the enhancement of excitation nonradiative transport in photonic devices.