Abstract
Scheelite type red phosphors CaLa~1βx~NbWO~8~: __x__Eu^3+^ (xβ=β0.01, 0.03, 0.05, 0.1, 0.15, 0.2, and 0.25) and CaLa~0.8βy~NbWO~8~: 0.2Eu^3+^, __y__Bi^3+^(yβ=β0.1, 0.15, and 0.2) were prepared by conventional solid state reaction route. The crystalline structure, morphology and absorbance of these phosphors were characterized by powder Xβray diffraction (XRD), scanning electron microscope (SEM), Fourier transform infrared (FTβIR), and UVβVisible absorption spectroscopy. Investigations on their photoluminescent properties indicated that both Eu^3+^ doped and Eu^3+^, Bi^3+^ coactivated samples emit strong red light at 615βnm under both near UV (394βnm) and blue (465βnm) excitations. Bi^3+^ codoped system showed broadened charge transfer band (CTB) and stronger excitation peaks at 394 and 465βnm. The red emission intensity of CaLa~0.8~NbWO~8~: 0.2Eu^3+^ phosphor is improved by a factor of 2 as 20βmol% Bi^3+^ is introduced into the system, and is four times stronger than that of the commercial Y~2~O~3~:Eu^3+^ red phosphor. These phosphors are characterized by sharp red emission with color coordinates closer to the standard red phosphors. Thus, the above phosphors could be a promising red candidate for the phosphor converted white light emitting diodes (pcβWLEDs).