Temperature of broadband anti-Stokes white emission in LiYbP4O12: Er nanocrystals

The up-conversion emission of LiYb0.99Er0.01P4O12 nanocrystals was investigated in vacuum upon the focused beam of infrared laser excitation. The intense white broad band emission was observed above the threshold power of 800 mW. An increase of excitation power results in enhancement of temperature of emitting nanocrystals. The temperature of nanocrystals was determined following the thermally equilibrated f-f emission transitions of Er3+ ions. The highest measured temperature of white emission was determined to be about 900 K. It is concluded that the black body radiation is not responsible for the white broad band emission. (C) 2014 AIP Publishing LLC.