Efficient UV-emitting phosphors based on cerium-activated calcium pyrophosphate and lamps containing the same
AssigneeGTE Laboratories Incorporated
InventorsThomas E. Peters, Romano G. Pappalardo, Alexandre Vetrovs
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Abstract
The present invention is directed to phosphors exhibiting efficient, narrow band UV emission, with peak emission at 330 nm (from excitation at 254). These phosphors are cerium-activated calcium pyrophosphate (beta-phase) of nominal formulation Ca(.sub.2-w-x-y) (NSF).sub.w Ce.sub.x Na.sub.y P.sub.2 O.sub.7 wherein: NSF is the non-stoicheometric factor; 0.ltoreq.w.ltoreq.0.1; 0.05.ltoreq.x.ltoreq.0.20; and 0.05.ltoreq.y.ltoreq.0.20.
Claims15
Efficient narrow band ultra-violet emitting phosphors consisting essentially of cerium activated calcium pyrophosphate beta-phase matrices having the general formula:
- Ca.sub.(2-w-x-y) (NSF).sub.w Ce.sub.x Na.sub.y P.sub.2 O.sub.7
- wherein:
- NSF is the non-stoicheometric factor;
- 0.ltoreq.w.ltoreq.0.1;
- 0.05.ltoreq.x.ltoreq.0.20;
- and
- 0.05.ltoreq.y.ltoreq.0.20;
- said phosphors being characterized by a peak emission at about 330 nm when excited by short wave ultra violet light of 254 nm.
An ultra-violet lamp comprising:
- (a) a sealed tubular envelope;
- (b) a discharge-sustaining filling including mercury contained within said envelope;
- (c) electrodes disposed within said envelope and operable when energized to sustain a discharge therebetween to generate ultra-violet radiation of about 330 nm;
- and
- (d) a phosphor coating disposed on the interior surface of said envelope, said phosphor coating having the nominal formula
- Ca.sub.(2-w-x-y) (NSF).sub.w Ce.sub.x Na.sub.y P.sub.2 O.sub.7
- wherein:
- NSF is the non-stoicheometric factor;
- 0.ltoreq.w.ltoreq.0.1;
- 0.05.ltoreq.x.ltoreq.0.20;
- and
- 0.05.ltoreq.y.ltoreq.0.20.
Dependencies are inferred from the claim text.