The δ value dependence of photoluminescence in green-emitting Ba3Si6O12−δN2+2/3δ:Eu2+ phosphors for white light-emitting diodes

Green emitting Eu2+-doped Ba3Si6O12−δN2+2/3δ phosphors with δ value varying in the range of −0.6 to 1.8 were synthesized by firing the raw materials of α-Si3N4, SiO2, BaCO3 and Eu2O3 at 1,350 °C for 12 h under a N2/H2 atmosphere. The solid-solution and luminescence properties of as-prepared Ba3Si6O12−δN2+2/3δ:Eu2+ phosphors were investigated by XRD, O/N automatic analyzer and UV–Vis spectrophotometer. The composition-dependent solid solution of Ba3Si6O12−δN2+2/3δ with small range of δ is established. The emission wavelength with a range of 522–545 nm by varying δ value as a function of dopant Eu2+ is observed in this phosphor. The emission band shows a shift to higher energy and a diverse quenching concentration with an increase of N/O ratio in Ba3Si6O12−δN2+2/3δ:Eu2+ phosphors. The measured results suggest that Ba3Si6O12−δN2+2/3δ:Eu2+ possesses broad applications as an effective green phosphor in producing white light-emitting diodes.