Optical analysis of Sr₃ Gd(PO₄ )₃ :Pr³⁺ phosphors for lighting applications

A series of praseodymium (Pr³⁺ ) ion activated Sr₃ Gd_(1-x) (PO₄ )₃ :xPr³⁺ (0 ≤ x ≤ 2.0 mol%) phosphors were prepared and their structural, compositional and luminescence properties were investigated. The X-ray diffraction profiles indicate that the studied phosphors crystallized into body centred cubic structure and the Pr³⁺ ions have no influence on Sr₃ Gd(PO₄ )₃ phase. The high-resolution scanning electron microscopy images show the agglomeration of particles that are inter-connected and form irregular shape Sr₃ Gd(PO₄ )₃ structures. The excitation transitions corresponding to Pr³⁺ :³ H₄  → ³ P_2,1,0 transitions at 445, 471 and 483 nm, respectively, matched well with the emission of blue-light-emitting diode (LED) chip. The emission spectra show strong reddish-orange luminescence through ¹ D₂  → ³ H₄ transition when excited at 445 nm blue wavelength. The synthesized phosphors have the potential to be used as reddish-orange lighting devices.