Luminescence and energy migration in a two-dimensional system: NaEuTiO4

Abstract

Energy transfer processes in compounds NaGd1~Eu~TiO4(0 cx~1) have been evaluated. It is shown that in these compounds energy migration to quenching centres occurs down to the lowest temperatures if x > 0.3. Transfer from intrinsic Eu 3~ions to extrinsic Eu3 + ions has been observed. The nature of quenching centres and trap centres has been clarified. The characteristics of the energy migration processes can be explained using a two-dimensional diffusion model. The temperature dependence of the hopping rate can be explained assuming phonon-assisted energy transfer.

Energy migration processes in phosphate nanocrystals: Size and dimensionality dependence

“…Both arrangement of regular RE ions [8,9] and size of nanocrystal can provide the sufficient modification of the process of electronic excitation energy migration. For the sufficient small sizes the nanocrystal surface can play a role of scattering impurities providing the localization of electronic excitation inside the "cage" and in this way leading to increase of the probability of electronic excitation energy capture by traps [10,11].…”