Sol–gel synthesis and photoluminescence studies on colour tuneable Dy3+/Tm3+ co-doped NaGd(WO4)2 phosphor for white light emission

摘要: Abstract A series of Dy 3+ /Tm ion co-doped NaGd(WO 4 ) 2 (NGW) phosphors were synthesised by a sol–gel method at low temperature for white light emission. The structural and luminescence properties the studied powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Raman photoluminescence techniques. In :NGW phosphors, dopant ions substituted Gd that are located in S sites NGW host lattice. host, under UV excitation have shown strong yellow ( F 9/2 → 6 H 13 /2 comparatively weak blue 15 emission transitions 575 and 488 nm, respectively. Due to deficient colour overall falls region. Hence, Tm having 455 nm corresponding transition 1 D 3 co-activated along with matrix. By changing doping concentrations NGW, was tuned 353 nm wavelength. Their co-ordinates calculated found be very close chromaticity (0.333, 0.333).