Efficient phosphor-conversion led structure
US6155699A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 15, 1999 |
| Grant date | Dec 5, 2000 |
| Priority date | — |
| Expiry date | Mar 15, 2019 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S362/80
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A light emitting device and a method of fabricating the device include a wavelength selective reflector that is formed between a light source and a layer of phosphorescent material. The light emitting device is a phosphor-conversion light emitting diode (LED) that outputs secondary light that is converted from primary light emitted from the light source. In the preferred embodiment, the light source is a Gallium Nitride (GaN) die and the wavelength selective reflector is a distributed Bragg reflector (DBR) mirror. The DBR mirror is comprised of multiple alternating layers of high and low refractive index materials. The high refractive index material may be Titanium Dioxide (TiO.sub.2) and the low refractive index material may be Silicon Dioxide (SiO.sub.2). An encapsulating layer over the GaN die provides a distance between the GaN die and the DBR mirror. Preferably, the encapsulating layer is a dome-shaped structure and the DBR mirror forms a dome-shaped shell over the encapsulating layer. In the most preferred embodiment, the dome-shaped configuration of the encapsulating layer and the DBR mirror is generally hemispheric. The dome-shaped configuration of the DBR mirror reduces th…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.