Crystal Structure and Photoluminescence Properties of Ca3(PO4)2:Eu3+ Phosphors With High Emission Efficiency

Luminescence. 2025 Jan;40(1):e70083. doi: 10.1002/bio.70083.

Abstract

The influence of Eu3+ concentration on the crystal structure and photoluminescence (PL) properties of Ca3-x(PO4)2:xEu3+ (0.06 ≤ x ≤ 0.10) phosphors is systematically investigated using X-ray diffraction (XRD) Rietveld refinement, scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectroscopy, UV-visible spectroscopy, and PL spectroscopy. The prepared phosphors exhibit a single rhombohedral phase with the space group R3c. The constituent ions occupy various crystallographic sites, including Ca(1-5), Eu(1-3), P(1-3), and O(1-10) sites. Under 397-nm excitation, the emission spectra show distinct emission peaks between 525 and 725 nm, corresponding to the 5D1 → 7Fj (j = 1 and 2) and 5D0 → 7Fj (j = 1, 2, 3, and 4) transitions of Eu3+ ions. The concentration quenching observed in the phosphors is attributed to electric multipolar interactions. Among the prepared phosphors, Ca2.92(PO4)2:0.08Eu3+ phosphor shows the highest emission efficiency and excellent color performance. These results demonstrate that Ca3-x(PO4)2:xEu3+ phosphors have significant potential as red-emitting materials for white light-emitting diode (WLED) applications.

Keywords: LED; climate change; crystal structure; optical properties; phosphor.

MeSH terms

  • Calcium Phosphates / chemistry
  • Europium* / chemistry
  • Luminescence*
  • Luminescent Agents* / chemical synthesis
  • Luminescent Agents* / chemistry
  • Luminescent Measurements
  • Molecular Structure
  • Spectroscopy, Fourier Transform Infrared
  • X-Ray Diffraction

Substances

  • Europium
  • Luminescent Agents
  • Calcium Phosphates