Preparation and photoluminescence of Tm3+/Eu2+/Eu3+ tri-doped fluorosilicate glass ceramics for warm WLED

Abstract Glass-ceramics (GCs) can effectively remedy heat accumulation of lighting applications induced by high power. During the preparation of traditional devitrified GCs, some active ions are unable to play their roles because they fail to enter the crystal lattice. In this work, a Tm3+/Eu2+/Eu3+ tri-doped fluorosilicate GC with thermal conductivity of 2.69 W m−1 K−1 was prepared for the warm WLED. Through the devitrified process, a fraction of Eu3+ ions are self-reduced to Eu2+ producing green light in the crystal phase, and residual Eu3+ ions, as well as Tm3+ ions, produce red and blue light in the glass matrix. Furthermore, the photoluminescence intensity of GC enhances more than 212% as the microcrystal precipitation in glass scatter increases. The obtained warm white light has a low correlated color temperature of 3986 K and high color rendering index of 91 under ultraviolet excitation. It is suggested that this type of GCs has a promising prospect in the high-power WLED field.