Photoluminescence Properties of Heavily Eu3+ -Doped BaCa2 In6 O12 Phosphor for White-Light-Emitting Diodes

Heavily Eu3+-doped BaCa2In6O12 phosphors were prepared by conventional solid-state reaction, and its structural properties were investigated by means of Rietveld refinement method using an X-ray source. XRD patterns confirm the hexagonal phase of BaCa2In6O12: Eu3+ phosphors. The obtained spectrum data indicate that the emission spectra of Ba1−xEuxCa2In6O12 samples excited at 393 nm exhibit a series of shaped peaks assigned to the 5D0,1,2,3 →7FJ (J = 0,1,2,3,4) transitions. Luminescence from the higher excited states, such as 5D1, 5D2, and 5D3, were also observed even though the Eu3+ concentration was up to x = 0.4. More importantly, the Ba1−xEuxCa2In6O12 phosphor still emits white luminescence, when the Eu3+ ion concentration is up to x = 0.07 before concentration quenching is observed, which shows that the phosphor is a promising single-phase phosphor for near ultraviolet (NUV) light-emitting diodes (LED). Furthermore, the temperature's impact on white luminescent properties was studied. Finally, a white-light-emitting diodes (W-LEDs) fabricated with the Ba0.95Eu0.05Ca2In6O12 phosphor incorporated with an encapsulant in ultraviolet LEDs (λmax = 395 nm) is discussed.