Light emitting device employing non-stoichiometric tetragonal alkaline earth silicate phosphors
US8134165B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 14, 2008 |
| Grant date | Mar 13, 2012 |
| Priority date | — |
| Expiry date | Mar 10, 2029 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/19107
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Disclosed is a light emitting device employing non-stoichiometric tetragonal Alkaline Earth Silicate phosphors. The light emitting device comprises a light emitting diode emitting light of ultraviolet or visible light, and non-stoichiometric luminescent material disposed around the light emitting diode. The luminescent material adsorbs at least a portion of the light emitted from the light emitting diode and emits light having a different wavelength from the absorbed light. The non-stoichiometric luminescent material has tetragonal crystal structure, and contains more silicon in the crystal lattice than that in the crystal lattice of silicate phosphors having stoichiometric crystal structure. The luminescent material is represented as the formula (BauSrvCawCux)3−y(Zn,Mg,Mn)zSi1+bO5+2b:Eua. Light emitting devices having improved temperature and humidity stability can be provided by employing the non-stoichiometric tetragonal Alkaline Earth Silicate phosphors.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.