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. 04, 2003
Filed:
Nov. 28, 2000
James Ibbetson, Goleta, CA (US);
Brian Thibeault, Santa Barbara, CA (US);
Cree Lighting Company, Goleta, CA (US);
Abstract
Naturally occurring polarization-induced electric fields in a semiconductor light emitter with crystal layers grown along a polar direction are reduced, canceled or reversed to improve the emitter's operating efficiency and carrier confinement. This is accomplished by reducing differences in the material compositions of adjacent crystal layers, grading one or more layers to generate space charges and quasi-fields that oppose polarization-induced charges, incorporating various impurities into the semiconductor that ionize into a charge state opposite to the polarization induced charges, inverting the sequence of charged atomic layers, inverting the growth sequence of n- and p-type layers in the device, employing a multilayer emission system instead of a uniform active region and/or changing the in-plane lattice constant of the material.