Li doping effect on the photoluminescence behaviors of KSrPO4:Dy3+ phosphors for WLED light

A novel warm-white phosphor KSrPO4 co-doped with Dy3+. and Li+ ions was prepared by solid state reaction. A strategy of Li+ doping was used with the aim of enhancing the luminescence of 475 nm and 570 nm emission bands under NUV excitation. Compared to lithium-free KSrPO4:Dy3+, the intensities of the 570 nm emission peaks were increased by 4.32 times and 2.84 times excited by 351 nm and 388 nm with 6 mol% Li+ ions co-doping, respectively. The mechanism of the enhancement was discussed, that is due to the improvement of the phosphors' crystallinity and charge compensation when the Li+ ions were introduced. Furthermore, the thermal stability of KSrPO4:0.01Dy(3+), 0.06Li(+) was measured and discussed, demonstrating it can be applied for high-powered LED. And the chromaticity coordinates of KSrPO4:0.01Dy(3+), xLi(+) can be tuned efficiently from the cold-white region to warm-white region with Li+ ions increasing, presenting its potential applied value as a new warm-white LED phosphor. (C) 2015 Elsevier Ltd. All rights reserved.