The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 21, 1993
Filed:
Jan. 30, 1992
Tetsuya Yagi, Itami, JP;
Tsuneo Okada, Itami, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
An AlGaAs/GaAs system light emitting device includes a GaAs substrate doped with a first conductivity type impurity, a first conductivity type Al.sub.y Ga.sub.1-y As first cladding layer, an Al.sub.x Ga.sub.1-x As (0 <x<y) active layer, and an Al.sub.y Ga.sub.1-y As second cladding layer having a second conductivity type opposite to the first conductivity type successively disposed on the substrate. The light emitting device includes an Al.sub.z Ga.sub.1-z As (z.gtoreq.0) buffer layer which is disposed between the GaAs substrate and the first cladding layer containing a dopant impurity in such a high concentration that the intensity of photoluminescent light generated due to the band-to-band transitions is reduced and has a smaller energy band gap than the energy of the light emitted from the light emitting device. Therefore, a long lifetime semiconductor light emitting device having no sub peak in the light emission spectrum can be easily produced with good yield.