The δ value dependence of photoluminescence in green-emitting Ba3Si6O12−δN2+2/3δ:Eu2+ phosphors for white light-emitting diodes
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Green emitting Eu2+-doped Ba3Si6O12−δ N2+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−δ N2+2/3δ :Eu2+ phosphors were investigated by XRD, O/N automatic analyzer and UV–Vis spectrophotometer. The composition-dependent solid solution of Ba3Si6O12−δ N2+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−δ N2+2/3δ :Eu2+ phosphors. The measured results suggest that Ba3Si6O12−δ N2+2/3δ :Eu2+ possesses broad applications as an effective green phosphor in producing white light-emitting diodes.
KeywordsCrystal Field Splitting Green Phosphor Broad Excitation Band Blue Light Excitation Crystal Field Strength
This work is supported by the National Natural Science Foundation of China (51102021), the Natural Science Foundation of Beijing (2102022) and the National High Technology Research and Development Program of China (2010AA03A404, 2011AA03A101).