A reinvestigation of luminescence properties of Bi3+-activated MSb2O6 (M = Ca, Sr) phosphors

The photoluminescence (PL) properties of Bi3+ in the MSb2O6 (M =Ca, Sr) have been reinvestigated. Our results are essentially different from the reported data. The PL spectra of MSb2O6:Bi consisted of an ultraviolet (UV) band due to P-3(1)-S-1(0) transition of isolated Bi3+ ions and a visible band due to Bi3+ pairs (clusters), which have not been reported with high intensities even at room temperature. In CaSb2O6:Bi the visible emission (443 nm) predominated over the UV emission (297 nm), while in SrSb2O6:Bi the visible emission (487 nm) had similar intensity to the UV emission (319 nm). The maximum visible emission intensity was at x = 0.0075 (x: the doping Bi concentration per mol of host) in MSb2O6:Bi (M = Ca, Sr), and the value in CaSb2O6:Bi was about six times higher than in SrSb2O6:Bi. The intense blue emission in CaSb2O6:Bi proves that the modified solid state reaction is a better method to synthesize a higher-performance CaSb2O6:Bi phosphor as a potential candidate for white-light-emitting diode pumped by UV chip (w-UVLED) and other display devices. (C) 2008 Elsevier B.V. All rights reserved.