White light emission from NaLa(PO3)4: Dy3+ single-phase phosphors for light-emitting diodes

Abstract White light emission phosphors NaLa(PO 3 ) 4 : Dy 3+ were synthesized by a solid-state method. XRD analysis confirmed that all the Dy 3+ doped phosphors are single phase. The photoluminescence excitation and emission spectra, concentration effect, decay property, and CIE coordinates were investigated. Strong excitation peaks of NaLa(PO 3 ) 4 : Dy 3+ were found around 350–400 nm, which matched well with those of the near-UV LED chips. Under 350 nm excitation the NaLa(PO 3 ) 4 : Dy 3+ exhibits intense white emission by combining the two emission peaks at 485 nm and 571 nm, attributed to the characteristic 4 F 9/2 – 6 H 15/2 and 4 F 9/2 – 6 H 13/2 transitions of Dy 3+ . The optimum doped concentration of Dy 3+ ions is around 6 mol% and the critical transfer distance of Dy 3+ is calculated as 15.4 A. In addition, the CIE chromaticity coordinates of NaLa(PO 3 ) 4 : Dy 3+ phosphors are (0.2923,0.3359). The results indicate that the NaLa(PO 3 ) 4 : Dy 3+ phosphors have great potential as a single-component white-light-emitting phosphor for UV-light-emitting diodes.