Fabrication and photoluminescence characteristics of novel red-emitting Ba2LuNbO6:Eu3+ double-perovskite phosphors on near UV WLEDs

Abstract Red emitting phosphor plays a significant role in accelerating the improvement of illumination quality for white light emitting diodes (WLEDs). In this work, by using solid-state reaction method, an efficient novel Ba2LuNbO6:Eu3+ phosphor with double-perovskite structure was successfully prepared. Here, a series of Ba2LuNbO6:Eu3+ red phosphors can be efficiently pumped by the near-ultraviolet (UV) light and then present high-brightness at orange emission (598 nm, 5D0→7F1) and red emission (610 nm, 5D0→7F2). The ratio values of 610 to 598 nm in Ba2LuNbO6:Eu3+ phosphors exceed 1 when the content of Eu3+ is larger than 0.4 mol, because the occupation of Eu3+ ions is changed from Lu3+ ions with symmetric sites to Ba2+ ions with asymmetric sites. Besides, the optimized concentration of Eu3+ at the 5D0→7F2 transitions is obtained when x=1, indicating that there is non-concentration quenching in Ba2LuNbO6:Eu3+ phosphors. Moreover, the CIE chromaticity coordinates of Ba2LuNbO6:Eu3+ was calculated to be of (0.587, 0.361), the color purity was calculated to be 72.26% and internal quenching efficiency (IQE) was measured to be 67%. Finally, the thermal stability of Ba2LuNbO6:Eu3+ phosphors was also studied. Our work demonstrates that the novel double-perovskite red-emitting Ba2LuNbO6:Eu3+ phosphors are prospective red emitting elements for WLEDs applications.