UV-emitting phosphor and lamp containing same
View Patent ↗A UV-emitting phosphor is described wherein the phosphor is excitable by vacuum ultraviolet radiation (VUV). The phosphor is a gadolinium-activated strontium magnesium aluminate which preferably has an excitation maximum at about 172 nm. The phosphor exhibits a narrow-band UV emission at about 310 nm which makes it useful for medical phototherapy applications.
1. A UV-emitting lamp comprising a discharge vessel containing a source of vacuum ultraviolet radiation and a UV-emitting phosphor on an interior wall of the discharge vessel, the UV-emitting phosphor comprising gadolinium-activated strontium magnesium aluminate.
2. The UV-emitting lamp of claim 1 wherein the source of vacuum ultraviolet radiation is a xenon excimer discharge.
3. The UV-emitting lamp of claim 2 wherein the discharge vessel has dielectrically impeded electrodes.
4. The UV-emitting lamp of claim 1 wherein the phosphor is represented by a formula Sr 1−x Gd x Al 12−y Mg y O 19 , where x ranges from about 0.03 to about 0.15 and y ranges from greater than 0 to about 0.2.
5. The UV-emitting lamp of claim 2 wherein the phosphor has an excitation maximum at about 172 nm.
6. The UV-emitting lamp of claim 4 wherein y ranges from x−0.02 to x+0.02.
7. The UV-emitting lamp of claim 4 wherein x is about 0.07.
8. The UV-emitting lamp of claim 1 wherein the phosphor contains magnesium in an amount from greater than 0 to about 0.2 moles Mg per mole of phosphor.
9. The UV-emitting lamp of claim 1 wherein the phosphor is coactivated with at least one of Ce and Pr.