Color tuneability behaviour and energy transfer analysis on Dy³⁺-Eu³⁺ co-doped glasses for NUV-WLEDs application

A series of Dy³⁺ and Eu³⁺ co-doped zinc aluminoborosilicate (ZABS) glasses were synthesized by a high-temperature melt-quenching method. Visible and NIR transitions of Dy³⁺-Eu³⁺ ions are observed through absorption spectra. A reverse trend in the optical band gap values and Urbach energy are seen with addition of Eu³⁺ ions. Photoluminescence studies recorded under different excitation wavelengths showed a variation in the emission intensities and prevailed the color tuneability behaviour of dopants. The energy transfer between Dy³⁺ and Eu³⁺ ions are studied through emission profiles, energy level diagram, and decay curves. The type of multipolar interaction between Dy³⁺ and Eu³⁺ are understood via Inokuti-Hirayama (IH) model and Dexter energy model. The CIE chromaticity coordinates, and correlated color temperature (CCT) values suggest that the prepared glasses can be used for light emitting diode application when excited at near-ultraviolet region.