Sr1.98Eu0.02SiO4 luminescence whisker based on vapor-phase deposition: Facile synthesis, uniform morphology and enhanced luminescence properties

A high performance strontium silicate phosphor has been successfully synthesized though a facile vapor-phase deposition method. The product consists of single crystal whiskers which are smooth and uniform, and with a sectional equivalent diameter of around 5 mu m; the aspect ratio is over 50 and no agglomeration can be observed. X-ray diffraction result confirmed that the crystal structure of the whisker was alpha'-Sr2SiO4. The exact chemical composition was Sr1.98Eu0.02SiO4 which was analyzed by energy dispersive spectrometer and inductively coupled plasma-mass spectrometer. The whisker shows broad green emission with peak at 523 nm ranging from 470 to 600 nm (excited at 370 nm). Compared with traditional Sr2SiO4:Eu phosphor, durability (at 85% humidity and 85 degrees C) and thermal stability of the whisker are obviously improved. Moreover, growth mechanism of the Sr1.98Eu0.02SiO4 whiskers is Vapor Liquid-Solid. On a macro-scale, the product is still powder which makes it suitable for the current packaging process of WLEDs. (C) 2015 Elsevier Ltd. All rights reserved.