Optical analysis of Sr 3 Gd(PO 4 ) 3 :Pr 3+ phosphors for lighting applications.

A series of praseodymium (Pr 3+ ) ion activated Sr 3 Gd (1-x) (PO 4 ) 3 :xPr 3+ (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 Pr 3+ ions have no influence on Sr 3 Gd(PO 4 ) 3 phase. The high-resolution scanning electron microscopy images show the agglomeration of particles that are inter-connected and form irregular shape Sr 3 Gd(PO 4 ) 3 structures. The excitation transitions corresponding to Pr 3+ : 3 H 4  →  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 D 2  →  3 H 4 transition when excited at 445 nm blue wavelength. The synthesized phosphors have the potential to be used as reddish-orange lighting devices.