| 摘要 |
A light emitting device comprising a light producing element configured to generate ultraviolet light having a wavelength of from about 250 nm to about 400 nm and a self-activating phosphor comprising an ordered oxyfluoride compound is provided. The nitrogen-free or nitrogen-containing ordered oxyfluoride compound has a formula: A3-3a/2RaMO4-δ1-w′F1-δ2-w—Nw where A is Sr alone or Sr mixed with Ba and/or Ca such that A comprises at least about ⅔ mole % of Sr and up to about ⅓ mole percent of Ba and/or Ca; R is a rare earth element or a mixture of rare earth elements; M is Al, Ga, In, W, Mo, Bi, or mixtures thereof; 0<a≦̸0.3; δ1 and δ2 are both from about 0.01 to about 0.1; and 0≦̸w≦̸0.05 such that 0≦̸w′≦̸0.1 and 0≦̸w″≦̸0.15. The ultraviolet light excites the self-activating phosphor such that the self-activating phosphor emits visible light having a wavelength of from about 380 to about 750 nm. |
