Method of making narrow-band UVB-emitting phosphors
US7288215B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 30, 2005 |
| Grant date | Oct 30, 2007 |
| Priority date | — |
| Expiry date | Jan 25, 2026 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J61/44
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method is provided for making narrow-band, UVB-emitting, (Y,Gd,Ce,Pr)Mg borate phosphors. The method involves the use of a mixed oxide co-precipitate which is combined with MgO and boric acid and fired twice to form the borate phosphor. The mixed oxide co-precipitate is formed by dissolving sources of Y, Gd, Ce, and optionally Pr, in an acid solution. Oxalic acid or ammonia is added to the solution (or vice versa) to form a co-precipitate of oxalates or hydroxides that are further fired to obtain a mixed oxide co-precipitate. The use of the mixed oxide co-precipitate improves homogeneity and yields a phosphor having a higher brightness with very little or no sticking between the fired cakes and the firing crucibles.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.