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. 06, 2007
Filed:
Jan. 06, 2006
Nobuyuki Tomita, Tokyo, JP;
Masayoshi Takemi, Tokyo, JP;
Akihito Ohno, Tokyo, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
The present invention provides a semiconductor light emitting device where a spatial change in an In composition ratio is small within a plane of an active layer and device properties such as efficiency of light emission are excellent, and a manufacturing method thereof. An active layer having an InGaN quantum well structure is formed in such a manner that a ratio of a photoluminescence light emission intensity at 300 K to a photoluminescence light emission intensity at 5 K becomes 0.1 or less. The ratio of the photoluminescence light emission intensity reflects the degree of the spatial change in an In composition ratio in a quantum confined structure. In addition, a smaller value indicates a higher spatial uniformity in the In composition ratio. Therefore, there is greater spatial uniformity in the In composition ratio in the active layer, increasing the probability of radiative recombination of carriers occurring, by making the ratio of photoluminescence light emission intensity 0.1 or less; thus, it becomes possible to obtain a semiconductor light emitting device having high efficiency in light emission.