Yellow-emitting gamma-Ca2SiO4:Ce3+, Li+ phosphor for solid-state lighting: luminescent properties, electronic structure, and white light-emitting diode application

Abstract

A new yellow-emitting gamma-Ca2SiO4:Ce3+, Li+ phosphor was synthesized via a solid-state reaction. The phosphor showed a strong yellow emission with a wide bandwidth of 135.4 nm under blue light excitation. Absorption and photoluminescence measurements and density functional theory calculations suggest that the luminescence of the phosphor can be attributed primarily to the transitions of 5d -> 4f (F-2(7/2) and F-2(5/2)) of Ce3+ ions occupying Ca(1) sites in the host crystal. White light-emitting diodes (LEDs) were fabricated by combining this phosphor with a blue LED, and excellent white light with a high color rendering index of 86 was created owing to the wide emission bandwidth of the phosphor. (C) 2012 Optical Society of America