Luminescent properties of Ca2BO3Cl:Eu2+ yellow-emitting phosphor for white light-emitting diodes

The Ca2BO3Cl:Eu2+ phosphor was synthesized by the general high temperature solid-state reaction and an efficient yellow emission under near-ultraviolet and blue excitation was observed. The emission spectrum shows a single intense broad emission band centered at 573 nm, which corresponds to the allowed f-d transition of Eu2+. The excitation spectrum is very broad extending from 350 to 500 nm, which is coupled well with the emission of UV LED (350-410 nm) and blue LED (450-470 nm). The measured emission of In-GaN-based Ca2BO3Cl:Eu2+ LED shows white light to the naked eye with a chromatic coordinate of (0.33, 0.36). The Ca2BO3Cl:Eu2+ is a very appropriate yellow-emitting phosphor for white LEDs. (c) 2007 Elsevier B.V. All rights reserved.