Wydział Chemii

Damian Pasiński

Eugeniusz Zych

Jerzy Sokolnicki

2016

Journal of Alloys and Compounds

668

194-199

10.1016/j.jallcom.2016.01.223

Naukowa

Angielski

Artykuł

In the present work, yttrium aluminum garnet Y₃Al₅O_12−xN_2x/x(YAGN) was obtained using aluminum nitride (AlN) as a source of aluminum. YAGN was doped with the Ce³⁺ions (YAGN:Ce) in concentrations from 0.5 to 14mol%. According to XRD analysis, the crystal structure of YAG is maintained with traces of Al₂O₃. Scanning electron microscope (SEM) studies showed that the nitrogen atoms are not quite uniformly incorporated into grains, which may easily lead to the formation of a number of various Y³⁺sites. This means that Ce³⁺ions can also occupy sites of different nitrogen/oxygen ratios. The probability of Ce³⁺entering different sites changes with the dopant concentration. The emission and excitation spectra of Ce³⁺exhibit concentration dependence. For concentrations in the range 0.5-7% emission bands are extended to longer and shorter wavelengths in comparison to the typical emission of Ce³⁺in YAG. With the increase in the concentration of active ions (10-14mol%) excitation bands show further widening, and the emission bands shift gradually toward longer wavelengths, reaching the value of 45nm for 14mol%. The usefulness of these phosphors for application in white LED technology is discussed on the basis of the quantum efficiency of the emissions, luminescence decay times, and thermal quenching of the Ce³⁺emission.

Oxonitride phosphor, YAG:Ce, Garnet, White LED, luminescence

http://dx.doi.org/10.1016/j.jallcom.2016.01.223

http://www.elsevier.com