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:
Apr. 14, 2009
Filed:
Oct. 28, 2005
Pleun Pieter Maaskant, Cork, IE;
Edmund Anthony O'carroll, Cork, IE;
Paul Martin Lambkin, Cork, IE;
Brian Corbett, Cork, IE;
Pleun Pieter Maaskant, Cork, IE;
Edmund Anthony O'Carroll, Cork, IE;
Paul Martin Lambkin, Cork, IE;
Brian Corbett, Cork, IE;
Abstract
An array of highly efficient micro-LEDs where each micro-LED is an integrated diode structure in a mesa, in which the mesa shape and the light-emitting region are chosen for optimum efficiency. A single one of the micro-LEDs includes, on a substrate and a semiconductor layer, a mesa, a light emitting layer, and an electrical contact. The micro-LEDs in this device have a very high EE because of their shape. Light is generated within the mesa, which is shaped to enhance the escape probability of the light. Very high EEs are achieved, particularly with a near parabolic mesa that has a high aspect ratio. The top of the mesa is truncated above the light-emitted layer (LEL), providing a flat surface for the electronic contact on the top of the semiconductor mesa. It has been found that the efficiency is high, provided the top contact has a good reflectivity value. Also, it has been found that efficiency is particularly high if the contact occupies an area of less than 16% of the truncated top mesa surface area. This feature also helps to achieve a more directional beam in the case of the device being an LED.