Substitutional effects of the anionic group systems [BO₃³⁻], [PO₄³⁻ ], and [SO₄²⁻] on the down-conversion photoluminescence properties of Y₂O₃:Er³⁺ nanophosphors

A series of Y₂O₃, Y₂O₃: Er³⁺ (1 %) and Y₂O₃-AG: Er³⁺ (1 %) (where AG = BO₃³⁻, PO₄³⁻, and SO₄²⁻) nanophosphors were prepared via a chemical combustion technique. The primary X-ray powder diffraction results showed that the Y₂O₃:Er³⁺ phosphor materials crystallized into a cubic standard structure, while the Y₂O₃-AG: Er³⁺ phosphor materials transformed to hexagonal and tetragonal structures for the [PO₄³⁻] and [BO₃³⁻]-based phosphors, respectively. However, no changes were observed for the [SO₄²⁻]-based phosphor materials. The scanning electron microscope micrographs revealed that the particles were formed in the nanometre range with different sizes and shapes. The fourier-transformed infrared spectra showed the presence of various structural groups in the pure Y₂O₃ and Y₂O₃-AG: Er³⁺ phosphors. In addition to that, the optical bandgap energy values were obtained using the diffuse reflection spectra (DRS) spectra and Kubelka-Munk function theory. Under UV-379 nm excitation for the Y₂O₃-AG: Er³⁺ phosphors, the Y₂O₃–SO₄: Er³⁺ emitted the most intense green light at 563 nm wavelength. The Commission Internationale de l'Elcairage colour coordinates and correlated color temperature values indicated that the Y₂O₃:Er³⁺, Y₂O₃-PO₄:Er³⁺, and Y₂O₃–SO₄:Er³⁺ phosphor materials are potential candidates for producing enhanced green color components in white light-emitting diode (w-LED) applications.