Riken Corporation

Tokyo Ohka Kogyo Co., Ltd.

Ulvac, Inc.

Marubun Corporation

Dai Nippon Printing Co., Ltd.

Toshiba Kikai Kabushiki Kaisha

Nippon Tungsten Co., Ltd.

Shibaura Machine Co., Ltd.

Dowa Holdings Co., Ltd.

Noritoshi Maeda

Hideki Hirayama

Masafumi Jo

Mitsunori Kokubo

Takaharu Tashiro

Ryuichiro Kamimura

Yamato Osada

Yukio Kashima

Eriko Matsuura

Yasuhiro Watanabe

Takeshi Iwai

Satoshi Shimatani

Takafumi Ookawa

Yasushi Iwaisako

Tsugumi Nagano

Kanji Furuta

Yohei Aoyama

A deep ultraviolet LED with a design wavelength &#x3bb;, including a reflecting electrode layer (Au), a metal layer (Ni), a p-GaN contact layer, a p-block layer made of a p-AlGaN layer, an i-guide layer made of an AlN layer, a multi-quantum well layer, an n-AlGaN contact layer, a u-AlGaN layer, an AlN template, and a sapphire substrate that are arranged in this order from a side opposite to the sapphire substrate, in which the thickness of the p-block layer is 52 to 56 nm, a two-dimensional reflecting photonic crystal periodic structure having a plurality of voids is provided in a region from the interface between the metal layer and the p-GaN contact layer to a position not beyond the interface between the p-GaN contact layer and the p-block layer in the thickness direction of the p-GaN contact layer, the distance from an end face of each of the voids in the direction of the sapphire substrate to the interface between the multi-quantum well layer and the i-guide layer satisfies &#x3bb;/2n(where &#x3bb; is the design wavelength and n1Deff is the effective average refractive index of each film of the stacked structure from the end face of each void to the i-guide layer) in the perpendicular direction, the distance being in the range of 53 to 57 nm, the two-dimensional reflecting photonic crystal periodic structure has a photonic band gap that opens for TE polarized components, and provided that the period a of the two-dimensional reflecting photonic crystal periodic structure satisfies a Bragg condition with respect to light with the design wavelength &#x3bb;, the order m of a formula of the Bragg condition: m&#x3bb;/n=2(where m is the order, &#x3bb; is the design wavelength, nis the effective refractive index of two-dimensional photonic crystals, and a is the period of the two-dimensional photonic crystals) satisfies 2&#x2264;m&#x2264;4, and the radius of each void is R, R/a satisfies 0.30&#x2264;R/a&#x2264;0.40.

Deep ultraviolet LED and method for producing the same

Provided is a deep ultraviolet LED with a design wavelength &#x3bb;, including an Al reflecting electrode layer, an ultrathin metal layer, and a transparent p-AlGaN contact layer that are sequentially arranged from a side opposite to a substrate, and a photonic crystal periodic structure provided in the range of the thickness direction of the transparent p-AlGaN contact layer. The photonic crystal periodic structure has a photonic band gap.

Deep ultraviolet LED and method for manufacturing the same

To improve light extraction efficiency of a deep ultraviolet light-emitting diode (DUVLED), a typical LED element has a single crystal substrate made of sapphire or AlN, The ultraviolet layer is arranged as a film stack having an n-type conductive layer, a recombination layer, and a p-type conductive layer. A stack of a p-type contact layer and a reflective electrode is disposed on the p-type conductive layer. The ultraviolet emission layer and a p-type contact layer are made of mixed crystal of AlN and GaN. The transmittance for the emission wavelength of the p-type contact layer is increased, and the light extraction efficiency is improved. Also an LED element whose p-type contact layer is configured in a layered structure and whose reflective electrode is patterned is provided. Moreover, an electric appliance having such LED elements is provided.

Ultraviolet light-emitting diode and electric apparatus having the same

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Saitama, Japan

Noritoshi Maeda