Near pure white light emission of CeO2-Dy2O3 co-doped K2O–MgO–B2O3–P2O5 glasses and glass-ceramics

Abstract

In this paper, the Ce3+/Dy3+ co-doped K2O–MgO–B2O3–P2O5 glasses (KMBP system) were produced, and the glass-ceramics (GC) were obtained by thermal treatment. The structure and fluorescent characteristics of the glasses and GC were analyzed by structural characterization, Judd-Ofelt (J-O) theory and photoluminescence spectra. Thermal analysis revealed that the KMBP system exhibited a stronger crystallization ability. The J-O parameters of the as-prepared glasses were found to all obey the order as Ω2 > Ω4 > Ω6. Spectral analysis showed that the glass doped with 0.5Ce3+/0.2Dy3+ rendered the nearly pure white light emission and featured a near-zero color purity of 1.23% as well as a correlated color temperature of 5071 K near that of daylight, standard white light and commercial WLEDs. The energy between Ce3+ and Dy3+ ions was transferred dominantly through dipole-dipole interactions, as determined by the Inokuti-Hirayama model. Additionally, the GC sample obtained from the parent glasses nucleated at 520 °C for 1 h and then crystallized at 590 °C for 0.5 h showed the optimal fluorescent properties. The higher activation energy Ea (0.302 eV) value of the GC sample implied that the Ce3+/Dy3+ co-doped KMBP glass-ceramics possessed stronger fluorescent thermostability. This indicates the potential of the as-prepared glass-ceramics for WLEDs.