Photoluminescence Properties of Heavily Eu ³⁺ ‐Doped BaCa ₂ In ₆ O ₁₂ Phosphor for White‐Light‐Emitting Diodes

Heavily Eu 3+ ‐doped BaCa 2 In 6 O 12 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 BaCa 2 In 6 O 12 : Eu 3+ phosphors. The obtained spectrum data indicate that the emission spectra of Ba 1− x Eu x Ca 2 In 6 O 12 samples excited at 393 nm exhibit a series of shaped peaks assigned to the 5 D 0,1,2,3 → 7 F J ( J = 0,1,2,3,4) transitions. Luminescence from the higher excited states, such as 5 D 1 , 5 D 2 , and 5 D 3 , were also observed even though the Eu 3+ concentration was up to x = 0.4. More importantly, the Ba 1− x Eu x Ca 2 In 6 O 12 phosphor still emits white luminescence, when the Eu 3+ 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‐ LED s) fabricated with the Ba 0.95 Eu 0.05 Ca 2 In 6 O 12 phosphor incorporated with an encapsulant in ultraviolet LED s (λ max = 395 nm) is discussed.