Comparative photoluminescence studies on the various trivalent rare-earth ions (Eu 3+ , Dy 3+ , Sm 3+ , and Pr 3+ ) activated single-host material for solid-state lighting applications

A series of rare-earth (europium, dysprosium, samarium, and praseodymium) ions were doped with various concentrations in the eulytite-type Ba 3 Bi 2 (PO 4 ) (here after referred to as BaBiPO) phosphate-based host material and were prepared by the conventional solid-state reaction method. The phase formation of the prepared phosphor was confirmed by powder X-ray diffraction pattern. The surface morphology of the as-prepared phosphors was analyzed by using scanning electron microscopy. The absorption, diffuse reflectance spectrum, and photoluminescence properties of these phosphate-based phosphors were studied. From the photoluminescence results, the maximum emission intensity was observed in BaBiPO, at x c = 0.16 for Eu 3+ ; at x c = 0.09 for Dy 3+ , at x c = 0.05 for Sm 3+ , and at x c = 0.04 for the Pr 3+ ions. The critical energy transfer distance values are 22.65, 19.78, 24.07, and 25 Å for the Eu 3+ , Dy 3+ , Sm 3+ , and the Pr 3+ ions, respectively. The luminescence lifetime and the quantum efficiency of all the BaBiPO: Ln 3+ phosphors were calculated. The CIE color coordinates of the Ln 3+ ions-activated BaBiPO phosphors are as follows ‘ x = 0.638, y = 0.361 for red,’ ‘ x = 0.329, y = 0.349 for near-white,’ ‘ x = 0.553, y = 0.445 for orange-red,’ and ‘ x = 0.473, y = 0.489 for yellow,’ for the Eu 3+ , Dy 3+ , Sm 3+ , and the Pr 3+ ions, respectively. The correlated color temperatures of the Eu 3+ , Sm 3+ , and the Pr 3+ ions-doped phosphors are located in the warm white region, whereas for the Dy 3+ ion-doped phosphors, it is located in the cold white region. The thermal stability of these phosphors was studied, and the activation energy values of these phosphors were calculated. From the observed photoluminescence results, these phosphate-based rare-earth-doped materials can be applicable for the red, near-white, orange-red, and the yellow-emitting phosphors for solid-state lighting applications.