Thermally stable red luminescence from Eu3+ -activated telluro zinc phosphate glass under near-ultraviolet light excitation for photonic applications.

ABSTRACT

Telluro zinc phosphate (TZP) glasses doped with different concentrations of Eu3+ ions were prepared and their physical, structural, and luminescence properties were studied in detail to reveal the utility of the as-prepared glass for white light-emitting diode (w-LED) applications. The broad hump in the diffraction pattern specified the amorphous behaviour of the TZP glass. The various vibrational shoulder linkages were characterized using the Fourier transform infrared (FT-IR) spectroscopy. The optical absorption spectrum was measured in the ultraviolet (UV)-visible (Vis) light region for the Eu3+ -doped TZP (TZPE) glass and the optical band gap was found to be 3.12 eV. Eu3+ -doped TZP glasses showed several emission peaks in the visible region including an intense red emission peak due to the 5 D0 →7 F2 transition under an excitation wavelength of λex  = 393 nm, which was matched with the emitting wavelength of the near-UV LED chip. Commission Internationale de I'Eclairage (CIE) chromaticity coordinates were situated in the red region and nearly matched with the coordinates of the commercial red phosphor (Y2 O3 SEu3+ ). The decay profile of the TZPE50 glass exhibited a single exponential fit with a decay time ( τ ) of 1.76 ms. Temperature-dependent photoluminescence (TDPL) studies demonstrate that the as-prepared glass consist of excellent thermal stability. The detailed analysis and results confirmed that the red-emitting TZPE glasses were potential candidates for white-LED and other photonic applications.