High power and temperature luminescence of Y3Al5O12:Ce3+ bulky and pulverized single crystal phosphors by a floating-zone method

Yellow Y3Al5O12:Ce3+ single crystal phosphor was grown through a floating zone method. It showed a broader blue excitation and yellow emission spectra with lower quantum efficiency due to large internal reflections but higher thermal stability due to high thermal conductivity than the conventional powder. With pulverizing the as-grown single crystal down to micron powder, its quantum efficiency was enhanced, while its lumen maintenance at high temperature (200 °C) was reduced due to a generation of more phonons, confirmed by temperature-dependent Raman spectra. The as-grown and pulverized single crystal samples were applied to a high-power blue laser diode, and thus they gave an excellent luminescence feasibility to a high-power lighting source.