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:
Jun. 12, 2001
Filed:
May. 11, 1999
Hiromitsu Abe, Kyoto, JP;
Rohm Co., LTD, Kyoto, JP;
Abstract
A semiconductor light-emitting device includes a substrate formed of an AlGaAs-base semiconductor material. A light-emitting layer forming portion of an AlGaInP-base compound semiconductor material is formed on the substrate so as to provide a light emitting layer. On the surface of the light-emitting layer forming portion, an window layer of an AlGaAs-base semiconductor material is provided. An upper electrode is formed on the upper-side layer in electrical connection therewith, while a lower electrode formed on the substrate in electrical connection therewith. The light-emitting layer forming portion is of an overlaid structure formed by a clad layer formed in a first conductivity type on the substrate. An active layer is formed on the clad layer to have a composition with a lower band gap energy than that of the clad layer. A clad layer is formed in a second conductivity type on the active layer to have the same composition as the first-conductivity clad layer. The light emitted by the light-emitting layer forming portion and traveling toward the substrate is absorbed less by the substrate, which is rather reflected for outer radiation on the light radiation side. As a result, the efficiency of light radiation is improved to offer a semiconductor light-emitting device with higher brightness.