Wavelength converter for an LED and LED containing same
US8937332B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 31, 2012 |
| Grant date | Jan 20, 2015 |
| Priority date | — |
| Expiry date | Jan 31, 2032 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/24942
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A wavelength converter for an LED is described that comprises a substrate of monocrystalline garnet having a cubic crystal structure, a first lattice parameter and an oriented crystal face. An epitaxial layer is formed directly on the oriented crystal face of the substrate. The layer is comprised of a monocrystalline garnet phosphor having a cubic crystal structure and a second lattice parameter that is different from the first lattice parameter wherein the difference between the first lattice parameter and the second lattice parameter results in a lattice mismatch within a range of ±15%. The strain induced in the phosphor layer by the lattice mismatch shifts the emission of the phosphor to longer wavelengths when a tensile strain is induced and to shorter wavelengths when a compressive strain is induced. Preferably, the wavelength converter is mounted on the light emitting surface of a blue LED to produce an LED light source.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.