Excellent Luminous Efficacy and Color Homogeneity of White Light-Emitting Diodes with YPO4:Ce3+:Tb3+ PhosphorVo Phu Thoai and Nguyen Doan Quoc AnhE3S Web Conf., 72 (2018) 02002DOI: https://doi.org/10.1051/e3sconf/20187202002