Warm white light generation from Dy3+ doped NaSr2Nb5O15 for white LEDs

Dy3+ doped NaSr2Nb5O15 series were firstly synthesized by solid-state reaction method. Crystal structure and characteristic luminescence properties are investigated in detail by X-ray diffraction refinement and photoluminescence spectra measurement. NaSr2Nb5O15:Dy3+ exhibits strong absorption in near ultraviolet-blue region and intense warm white emission with CIE chromaticity coordinates (0.396, 0.433) and low correlated color temperature (3970 K) upon 388 nm excitation. The warm white LED has also been fabricated by combining with GaN (365-370 nm chip) and single NaSr2Nb5O15:Dy3+ phosphor. The results show that NaSr2Nb5O15:Dy3+ could be a promising phosphor for warm white LEDs. (C) 2012 Elsevier B.V. All rights reserved.