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:
Feb. 08, 2005
Filed:
Oct. 21, 2002
Nai-chuan Chen, Taipei, TW;
Yi-lun Chou, Taipei, TW;
Nae-guann Yih, Tao-Yuan, TW;
Uni Light Technology Inc., Tao-Yuan, TW;
Abstract
An AlGaInP light emitting diode with improved illumination is provided. The AlGaInP light emitting diode includes a semiconductor substrate, a light re-emitting layer, an AlGaInP layer with a first doping concentration, an AlGaInP lower cladding layer with a second doping concentration less than the first doping concentration, an undoped AlGaInP active layer, an AlGaInP upper cladding layer, a window layer, an annular-shaped top electrode on the window layer and a layered electrode on a bottom of the semiconductor substrate. The light re-emitting layer includes at least a first region formed of the light re-emitting layer and a second region formed of AlOenclosing the first region. Since AlGaInP layer between the AlGaInP lower cladding layer and the light re-emitting layer has the first doping concentration larger than that of the AlGaInP lower cladding layer, the AlGaInP layer provides a transverse current spreading. The AlOregion also improves light reflection illuminating on the light re-emitting layer. As a result, the brightness performance of the light emitting diode is improved.