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Hiroaki Okagawa

Researcher at Mitsubishi

Publications -  140
Citations -  2917

Hiroaki Okagawa is an academic researcher from Mitsubishi. The author has contributed to research in topics: Layer (electronics) & Semiconductor. The author has an hindex of 27, co-authored 140 publications receiving 2883 citations. Previous affiliations of Hiroaki Okagawa include Mitsubishi Chemical Corporation.

Papers
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High Output Power InGaN Ultraviolet Light-Emitting Diodes Fabricated on Patterned Substrates Using Metalorganic Vapor Phase Epitaxy

TL;DR: In this paper, a patterned sapphire substrate (PSS) with parallel grooves along the SA direction was fabricated by standard photolithography and subsequent reactive ion etching (RIE).
Journal ArticleDOI

Internal quantum efficiency of highly-efficient InxGa1−xN-based near-ultraviolet light-emitting diodes

TL;DR: In this article, the internal quantum efficiency (IQE) of highly-efficient near-UV light-emitting diodes, which shows an external quantum efficiency of 43% at 406 nm, has been measured by excitation power and temperature-dependent photoluminescence (PL).
Patent

GaN single crystal

TL;DR: A GaN single crystal having a full width at half-maximum of the double-crystal X-ray rocking curve of 5-250 sec and a thickness of not less than 80 μm was presented in this paper.
Patent

Semiconductor base and its manufacturing method, and semiconductor crystal manufacturing method

TL;DR: In this article, a growth plane of substrate 1 is processed to have a concavo-convex surface, and a crystal unit 20 occurs when the crystal growth is started, and then films grown in the lateral direction from the upper part of the convex part 11 as a starting point are connected to cover the concave surface of the substrate 1, leaving a cavity 13 in the concava part, thereby giving a crystal layer 2, whereby the semiconductor base is obtained.
Patent

Nitride semiconductor light emitting element

TL;DR: In this paper, a large chip type GaN-based light emitting element having a light emitting pattern unlike before, for which etching workability is improved, is provided. But, it is not shown how to obtain a light emitter in a mesh shape.