ABSTRACT
Previous work report that the quenching concentration is increased for the nanosized Y20,:Eu compared to that of the bulk. The main reason is that the nanostructure introduces much more interface and the energy transfer is blocked, i.e., less energy is depleted through the nonradiative center. From this postulation, the quenching concentration should increase with decreasing particle size. The recent results are contradicted and the real mechanism is under debate. For the combustion method, the quenching concentration increased from -5 % to 10% for [G]/[RE] from 1 to 1.3. Increasing [G]/[RE] will not increase the quenching concentration any more. Although the relationship is not certain, the quenching concentration of the nanosized material is higher than the corresponding bulk is doubtless. This phenomenon suggests that the large volume-surface ratio induced surface states is not the main factor for nonradiative recombination.
