A tunable yellow emission from three-band emission of singly doped single-phased phosphor BaY2S4:Ho3+

The establishment of an approach to design tunable yellow emission through singly doped single-phased phosphors to obtain white LED-based InGaN chip was reported. BaY2-xS4:xHo3+ phosphors were prepared by the high temperature solid state reaction and characterized by X-ray diffraction and photoluminescence spectra. Under the excitation of 465 nm, the emission spectra of these phosphors exhibited three sharp emission lines peaked at about 492, 543 and 661 nm of Ho3+ corresponding to 5F3, 5F4 (5S2) and 5F5→5I8 transitions, respectively, with comparable intensities, resulting in a yellow light emission. The luminescence mechanism for Ho3+ in BaY2S4 was explained.