Light emitting diode with surface emission
US4570172A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 19, 1983 |
| Grant date | Feb 11, 1986 |
| Priority date | — |
| Expiry date | Dec 19, 2003 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10H20/813
Abstract
A light emitting diode (LED) is provided which has light emission taking place through the surface of a window layer and which consist of at least one active layer between a substrate and a window layer. Under biassing, the active layer emits isotropic radiation of wave length .lambda.. The LED of the invention comprises a re-emitting layer which absorbs the part of the radiation which is emitted in the direction of the substrate and re-emits it isotropically with a wave length very close to that of the active layer. For that, the re-emitting layer is made from a material whose prohibited band height is very close to but less than that of the active layer. If the substrate is transparent, it may be situated between the emitting layer and the re-emitting layer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.