Novel Eu2+-activated thiogallate phosphors for white LED applications: structural and spectroscopic analysis

Abstract

Novel Eu2+-activated BaGa2SiS6 and Ba2Ga8SiS16 thiogallate phosphors were prepared by solid-state reaction route. The BaGa2SiS6:Eu2+ phosphor generated a green emission upon excitation at 405 nm, whereas the Ba2Ga8SiS16:xEu(2+) phosphor could be tuned from cyan to green range with increasing Eu2+ concentration upon excitation at 365 nm. Additionally, the thermal luminescence properties of the thiogallate phosphors were investigated in the temperature range of 25 to 250 degrees C. A warm-white LED is fabricated using the combination of a 405 nm blue InGaN-based LED chip with the green-emitting BaGa2SiS6:0.01Eu(2+) phosphor, and red-emitting Sr2Si5N8:Eu2+ commercial phosphor with the CRI value of approximate to 88 and the CCT of 4213 K.