초록 |
This reports on synthesis and luminescence properties of divalent europium in Ba3Si6O12N2. Europium-doped Ba3Si6O12N2 powders were synthesized by sintering at 900 - 1300°C for 3 h under the atmosphere of H2/N2. A single, intense, broad emission band, centered at 525 nm, is observed due to the electronic transitions from the excited state 4f63d1 to the ground state 4f7 of Eu2+. The luminescence of Eu2+ in Ba3Si6O12N2 occurs at relatively low energy, which is attributable to the large crystal field splitting and nephelauxetic effect due to the nitrogen coordination of Eu2+. The dependence of luminescence properties on the Eu2+ concentration, chemical composition, and sintering is discussed. It is suggested that this green phosphor could be applied in light-emitting diodes (LEDs) for LCD back-light-units when combined with a red phosphor and a blue LED. |