Light emitting diodes with graded composition active regions

US7345324B2 · kind B2 · utility

Assignee

• Philips Lumileds Lighting Company LLC · US

Inventors

• David P. Bour · Cupertino, US
• Nathan Gardner · Mountain View, US
• Werner Goetz · Palo Alto, US
• Stephen A. Stockman · معلمی نژاد, US
• Tetsuya Takeuchi · Yokohama, JP
• Ghulam Hasnain · Palo Alto, US
• Christopher Kocot · Redwood City, US
• Mark R. Hueschen · Los Altos, US

Key dates

• Filing date: Jul 7, 2005
• Grant date: Mar 18, 2008
• Expiry date: Sep 25, 2025

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10H20/812

Abstract

A light emitting device in accordance with an embodiment of the present invention includes a first semiconductor layer of a first conductivity type having a first surface, and an active region formed overlying the first semiconductor layer. The active region includes a second semiconductor layer which is either a quantum well layer or a barrier layer. The second semiconductor layer is formed from a semiconductor alloy having a composition graded in a direction substantially perpendicular to the first surface of the first semiconductor layer. The light emitting device also includes a third semiconductor layer of a second conductivity type formed overlying the active region.