Rapid synthesis of Ce3+:YAG via CO2 laser irradiation combustion method: Influence of Ce doping and thickness of phosphor ceramic on the performance of a white LED device

Abstract

A new, rapid method was reported to produce Y3Al5O12 phosphors doped with different concentrations of Ce3+ (YAG:Ce3+) within 1.5 ​min via continuous-wave CO2 laser irradiation, in which a CO2 laser is utilised as the combustion source. X-ray powder diffraction confirmed the formation of pure cubic phase in the as-synthesised powder. Thus, laser irradiation plays an important role in optimising reaction kinetics to obtain high-quality crystal with high luminescence intensity. Furthermore, the incorporation of Ce3+ ions into the YAG matrix can be enhanced through sintering powders at 1050 ​°C for 5 ​h. Optical properties were examined comparatively using photoluminescence emission. Additionally, the performance of white light-emitting diode (LED) can be regulated easily by altering the Ce3+ doping concentration and YAG:Ce3+ layer thickness on blue InGaN LED chip. Excellent white light, which has a CIE coordinate of (0.31, 0.36) that approached the standard WLED values, a colour rendering index of about 69.4, a correlated colour temperature of about 6299 ​K and a luminous radiation efficiency exceeding 169 lm/W, was obtained for YAG doped with 2 ​mol% Ce concentration with a coating layer thickness of 1 ​mm.