Fabrication, photoluminescence, and potential application in white light emitting diode of Dy~(3+)-Tm~(3+) doped transparent glass ceramics containing GdSr_2F_7 nanocrystals

摘要

Dy~(3+)-Tm~(3+) doped transparent glass ceramics containing GdSr_2F_7 nanocrystals were fabricated successfully by a melt-quenching method and subsequent heating. X-ray diffraction and transmission electron microscopy analyses show that tetragonal GdSr_2F_7 nanocrystals are homogeneously precipitated among the borosilicate glass matrix. If excited with 354 nm UV light, the photoluminescence spectrum of Dy~(3+) single-doped transparent glass ceramics shows white-light emission. With doping of Tm~(3+), the overall emission color of Tm~(3+)-Dy~(3+) co-doped transparent glass ceramics can be tuned from white to blue through energy transfer between Dy~(3+) and Tm~(3+). CIE chro-maticity and color temperature measurements show that the resulting TGCS may be a candidate as a white LED material pumped by a UV InGaN chip.