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:
Aug. 05, 2003
Filed:
Jun. 02, 2000
Shigeki Hashimoto, Kanagawa, JP;
Katsunori Yanashima, Kanagawa, JP;
Masao Ikeda, Kanagawa, JP;
Hiroshi Nakajima, Kanagawa, JP;
Sony Corporation, Tokyo, JP;
Abstract
A semiconductor light emitting device using nitride III-V compound semiconductors is improved to reduce the threshold current density with almost no increase of the operation voltage. In a GaN semiconductor laser as one version thereof, the p-type cladding layer is made of two or more semiconductor layers different in band gap, and a part of the p-type cladding layer near one of its boundaries nearer to the active layer is made of a semiconductor layer having a large band gap than that of the remainder part. More specifically, in a AlGaN/GaN/GaInN SCH-structured GaN semiconductor laser, a p-type AlGaN cladding layer is made of a p-type Al Ga N layer in contact with a p-type GaN optical guide layer, and a p-type Al Ga N layer overlying the p-type Al Ga N layer (where 0≦x2<x1≦1).