Method of preparing zinc sulfide phosphor coactivated with copper and gold
US4208299A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 31, 1978 |
| Grant date | Jun 17, 1980 |
| Priority date | — |
| Expiry date | Jan 31, 1998 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09K11/642
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A zinc sulfide phosphor having no segregated free sulfides of copper and gold on the surface layer thereof, which contains 0.003 to 0.03% by weight of copper and 0.01 to 0.2% by weight of gold as co-activators and further 0.0025 to 0.04% by weight of aluminum each on the basis of the zinc sulfide. The chromaticity of the emission from the phosphor is in the range of x=0.310 to 0.350 and y=0.560 to 0.600 on CIE chromaticity coordinates. A method for the preparation of this zinc sulfide phosphor which comprises adding aluminum fluoride as the aluminum ion source and ammonium iodide as the flux compound to powdery raw material for phosphor composed of zinc sulfide and the activator compounds, and firing the formed mixture in a reducing sulfurous atmosphere, thereby removing any segregated free sulfides of copper and gold.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.