Multiple wavelength light emitting device
US5077588A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 28, 1990 |
| Grant date | Dec 31, 1991 |
| Priority date | — |
| Expiry date | Sep 28, 2010 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10H20/824
Abstract
A multiple wavelength light emitting device having a single p-n junction and at least two light emitting layers within a diffusion region of a minority carrier comprises a p-type Ga.sub.1-x1 Al.sub.x1 As layer, a p-type Ga.sub.1-x2 Al.sub.x2 As layer, a p-type Ga.sub.1-x3 Al.sub.x3 As layer, and an n-type Ga.sub.1-y Al.sub.y As layer, where x.sub.1, x.sub.2, x.sub.3 and Y represent aluminum arsenide mixed crystal ratios of the respective layers. The light emitting alyers, i.e., the p-type Ga.sub.1-x2 Al.sub.x2 As layer and the p-type Ga.sub.1-x3 Al.sub.x3 As layer each have a different band gap to emit an infrared light and a visible light, respectively. Since the infrared and ivsible lights are simultaneously emitted, emission of the infrared light can be confirmed or monitored by the visible light. The light emitting device of the present invention utilizes an energy well for trapping electrons and an energy barrier for preventing electrons from diffusing to improve the whole light emitting efficiency.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.