Light-emitting diode with a thick transparent layer

US5233204A · kind A · utility

Assignee

• Hewlett-Packard Company, L.P. · US

Inventors

• Robert M. Fletcher · San Jose, US
• Kuo-Hsin Huang · Banluliao, TW
• Chihping Kuo · Milpitas, US
• Jiann Yu · Palo Alto, US
• Timothy D. Osentowski · San Jose, US

Key dates

• Filing date: Jan 10, 1992
• Grant date: Aug 3, 1993
• Expiry date: Jan 10, 2012

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10H20/013

Abstract

A light emitting diode (LED) including a light generation region situated on a light-absorbing substrate also includes a thick transparent layer which ensures that an increased amount of light is emitted from the sides of the LED and only a minimum amount of light is absorbed by the substrate. The thickness of the transparent layer is determined as a function of its width and the critical angle at which light is internally reflected within the transparent layer. The thick transparent layer is located either above, below or both above and below the light generation region. The thick transparent layer may be made of materials and with fabrication processes different from the light generation region.