Method for making high-efficacy and long life electroluminescent phophor
US6361864B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 2, 1999 |
| Grant date | Mar 26, 2002 |
| Priority date | — |
| Expiry date | Feb 2, 2019 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/2993
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
A method of coating phosphor particles by chemical vapor deposition. The phosphors are coated by introducing an inert gas into a reaction vessel; charging phosphor particles into the reaction vessel; heating the reaction vessel to a reaction temperature; introducing a coating precursor which includes carbon into the reaction vessel for a time sufficient to saturate the phosphor particles with the precursor; continuing precursor flow into the reaction vessel; introducing an oxygen/ozone mixture into the reaction vessel, the oxygen/ozone mixture comprising less than 4.4 wt. % ozone; and maintaining the inert gas flow, oxygen/ozone mixture flow and further precursor supply for a time sufficient to coat the phosphor particles. The process produces phosphors having from 2200 to 6300 ppm of carbon on the coating and provides lamp efficacy's of greater than 6.1 lm/watt.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.