Novel yellowish-orange Sr8Al12O24S2:Eu2+ phosphor for application in blue light-emitting diode based white LED

Abstract

A new yellowish-orange phosphor, Sr8Al12O24S2:Eu2+, was synthesized by the solid-state method and its photoluminescence properties were investigated by excitation and emission spectra. Its excitation band is extending from 400-500 nm, which is adaptable to the emission band of blue LED chips (450-470 nm). Upon the excitation of 450 nm light, the phosphor exhibits strong yellowish-orange emission centered at 605 nm with good thermal stability. A white light-emitting diode (W-LED) that consists of a blue LED chip (similar to 470 nm) and a (Sr0.92Eu0.08)(8)Al12O24S2 phosphor is demonstrated. The CIE 1931 chromaticity coordinates (x, y) are (0.34, 0.25), the correlated color temperature (CCT) is 4300 K, and the luminous efficacy of this W-LED is 14.2 1m/W at room temperature and with a forward-bias current of 400 mA. (C) 2010 Optical Society of America