Energy transfer and color tunability in high-thermal-stability Dy3+/Tb3+ co-doped K3YF6 transparent oxyfluoride glass ceramics

The production process and comprehensive analysis of the co-doping of Dy3+ and Tb3+ in K3YF6 oxyfluoride glass-ceramics (GCs) are delved. The primary focus is on investigating the luminescent properties and energy transfer (ET) mechanisms within these systems. The embedding of well-formed K3YF6 nanocrystals within the matrix was verified through detailed analyses using X-ray diffraction (XRD) and transmission electron microscopy (TEM). Fine-tuning the Tb3+ concentration facilitated the achievement of tunable emission, ranging from a subtle yellow to a yellowish green hue, demonstrating the remarkable flexibility in color manipulation. Fluorescence analysis unmistakably demonstrates the occurrence of energy transfer occurring between Dy3+ and Tb3+ ions, attaining a peak energy transfer efficiency of 51.33 %. Additional analysis applying Dexter's energy transfer formula affirms that the fundamental mechanism of energy transfer between Dy3+ and Tb3+ ions is dipole-dipole interaction. The K3YF6 glass ceramics (GCs) incorporating Dy3+/Tb3+ nanocrystals exhibit a remarkable thermal stability, retaining 89.07 % of their original relative emission intensity at 423 K when stimulated by 350 nm light. These findings indicate that Dy3+/Tb3+ co-doped K3YF6 GCs hold significant potential in solid state lighting, positioning them as a candidate for future lighting.