Luminescence Properties and Energy Transfer Processes in Nanosized Cerium Doped YAG.

Luminescence properties of cerium doped Y3 Al5 O12 (YAG) nanocrystals in form of nanopowders and nanoceramics have been studied. The comparative analysis of luminescence characteristics for nano- and single-crystals has been done. It was detected that an excitonic mechanism of the energy transfer from the host lattice to cerium ions does not work in nanopowders and nanoceramic. It was also shown that antisite-related and self-trapped exciton-related luminescence bands are suppressed strongly in nanopowders, and it can be excited only under certain circumstances. These bands practically disappeared in the nanoceramic samples. It was suggested that nanoparticle's surface, which is an efficient trap for excitons and charge carriers, plays the crucial role in peculiarities of luminescence characteristics in nanocrystals. [ABSTRACT FROM AUTHOR]