Photoluminescence enhancement of Ce:YAG nanophosphors via doped/intrinsic core/shell structures

Ce:YAG/YAG nanophosphors are synthesized using a two-step seed mediated glycothermal process. The need for the proposed process arises from the high sensitivity of Ce3+ to its local environment, the highly defective surfaces of nanoparticles, and increased proportion of Ce atoms near the surface due to the high ratio of surface area to volume of nanoparticles. Shell thickness was controlled by varying the molar concentration of material added during the second step of synthesis relative to the starting amount, denoted as the shell-to-seed ratio (SSR). It was found that an SSR of 1:1 yielded an average particle size of 186 ± 59 nm with a marked enhancement in photoluminescence and photostability compared to particles with no shell. EELS linescans confirm localization of the dopant to the core of the crystal.