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:
Oct. 15, 1991
Filed:
Nov. 30, 1989
Hans Lobentanzer, Munich, DE;
Wolfgang Stolz, Ammerbusch, DE;
Klaus Ploog, Stuttgart, DE;
Julien Nagle, Hackensack, NJ (US);
Max-Planck Gesellschaft zur Forderung der Wissenschaften e.V., Gottingen, DE;
Abstract
A multiple quantum well light emitting compositional semiconductor device ch as a laser diode or a light emitting diode has an active region comprising an alternating sequence of layers of well layer material and of barrier layer material. The thickness of the barrier layer and of the adjacent well layers is chosen such that for one type of charge carrier a relatively high probability exists for such charge carriers to be present in the barrier region whereas the other type of charge carriers are localized in the potential wells. In this way it is possible to reduce the probability of non-radiative Auger recombination processes occurring thus reducing the threshold current and increasing the quantum efficiency of the device. This is particularly important since material systems with a small bandgap which lase at long wavelengths suitable for optical fibre transmission normally suffer performance penalties due to non-radiative Auger recombination and these penalties can be substantially reduced by tailoring the layer thicknesses to achieve the described probability distributions.