Thermally stable luminescence of blue LiSrPO4:E2+ phosphor for near-UV light-emitting diodes

Blue phosphor, LiSrPO4: Eu2+, was prepared by solid- state reaction method under a weak reductive atmosphere and investigated by means of photoluminescence, concentration quenching process, and temperature dependence of luminescence. These results show that LiSrPO4: Eu2+ can be efficiently excited by the UV- visible light of 250 - 440 nm and exhibits bright blue emission. Furthermore, Eu2+- doped LiSrPO4 phosphor shows high thermally stable luminescence comparable to commercial phosphor BaMgAl10O17: Eu2+ ( BAM). Two bright blue LEDs were fabricated by incorporating an InGaN- based near- UV chip with the obtained phosphor LiSrPO4: Eu2+ and BAM, respectively. Their luminescence properties were compared based on different forward- bias currents. All the characteristics suggest that LiSrPO4: Eu2+ is a good blue phosphor candidate for creating white light in phosphor- conversion white LEDs.