Impact of Eu3+ Dopants on Optical Spectroscopy of Ce3+: Y3Al5O12-Embedded Transparent Glass-Ceramics

Abstract

Transparent glass-ceramics containing Ce3+: Y3Al5O12 phosphors and Eu3+ ions were successfully fabricated by a low-temperature co-sintering technique to explore their potential application in white light-emitting diodes (WLEDs). Microstructure of the sample was studied using a scanning electron microscope equipped with an energy dispersive X-ray spectroscopy. The impact of co-sintering temperature, Ce3+: Y3Al5O12 crystal content and Eu3+ doping content on optical properties of glass-ceramics were systematically studied by emission, excitation spectra, and decay curves. Notably, the spatial separation of these two different activators in the present glass-ceramics, where Ce3+ ions located in YAG crystalline phase while the Eu3+ ones stayed in glass matrix, is advantageous to the realization of both intense yellow emission assigned to Ce3+: 5d→4f transition and red luminescence originating from Eu3+: 4f→4f transitions. As a result, the quantum yield of the glass-ceramic reached as high as 93%, and the constructed WLEDs exhibited an optimal luminous efficacy of 122 lm/W, correlated color temperature of 6532 K and color rendering index of 75.