Sanken Electric Co., Ltd.

Hitoshi Murofushi

Shiro Takeda

Koji Otsuka

Koji Ohtsuka

Takaya Ueno

Yoshinori Tanaka

Osamu Machida

Tetsuji Moku

Hidekazu Aoyagi

Kazuyoshi Haga

Masanori Hoshino

Nobuhisa Sugimori

Emiko Chino

Tsutomu Yokota

Yuichi Sato

Hideyuki Watanabe

Yoshihiko Uchida

A light emitting device () includes: three or more light emitting units () that individually include blue light emitting element, a wavelength range of the blue light emitting element accommodated in respective packages being different from each other. The light emitting device mixes output lights from the light emitting units () to output white light of a predetermined chromaticity. In an xy chromaticity diagram, the chromaticity of the output light from each of light emitting units () is located at a distance from the predetermined chromaticity. The difference between the chromaticity of the output light from each of the light emitting units () and the predetermined chromaticity is not greater than 0.04.

Light emitting device and lighting device

A light emitting device includes: a substrate (); blue light emitting elements () arranged on the main surface of the substrate (); and a phosphor sheet () containing a phosphor that is excited by emission light from the blue light emitting elements and emits excitation light, the phosphor sheet () being disposed above the blue light emitting elements (), wherein the blue light emitting elements () includes first blue light emitting elements () which emit first emission light having a first wavelength taken as a peak wavelength of a light emission spectrum, and second blue light emitting elements () which emit second emission light having a second wavelength taken as a peak wavelength of a light emission spectrum, and the second wavelength being a longer wavelength than the first wavelength by a wavelength difference of at least 10 nm.

Light emitting device

A light emitting device includes: a first blue light emitting element and a second blue light emitting element, peak wavelengths of which are different from each other, and a fluorescent substance layer comprising: a green fluorescent substance, which is excited by emission lights from the first blue light emitting element and the second blue light emitting element to emit green lights having emission spectrums having a first wavelength indicating a first intensity and a second wavelength indicating a second intensity smaller than the first intensity, respectively; and a red fluorescent substance, which has an absorption spectrum in which absorption is less in the second wavelength than in the first wavelength and which is excited by the emission lights from the first blue light emitting element and the second blue light emitting element to emit red lights.

A light emitting device includes: a first semiconductor region; a second semiconductor region and third semiconductor region which are provided in the first semiconductor region; a first semiconductor light emitting element of which first electrode is electrically connected to a main surface of the second semiconductor region; a second semiconductor light emitting element of which third electrode is electrically connected to a main surface of the third semiconductor region; and a conductor which electrically connects the second electrode of the first semiconductor light emitting element and the third semiconductor region, and which electrically connects the second electrode and the third electrode through the third semiconductor region. In the light emitting device, the semiconductor light emitting elements are connected in series, and are directly connected to a power source.

An array of LEDs are grown by epitaxy on row-connecting conductor strips extending in parallel spaced relationship to one another on the surface of a semiconductor substrate and are thereby electrically interconnected in rows. The row-connecting conductor strips are formed by ion implantation of a p-type dopant into parts of an n-type silicon substrate. Column-connecting conductor strips extend over the light-emitting surfaces of the LEDs for electrically interconnecting them in columns. The LEDs are lit up individually by voltage application between one of the row-connecting conductor strips and one of the column-connecting conductor strips.

LED array for microdisplays or like application

A high electron mobility transistor is disclosed which has a main semiconductor region formed on a silicon substrate. The main semiconductor region is a lamination of a buffer layer on the substrate, an electron transit layer on the buffer layer, and an electron supply layer on the electron transit layer. A source, drain, and gate overlie the electron supply layer. Also formed on the electron supply layer is a surface-stabilizing organic semiconductor overlay which is of p conductivity type in contrast to the n type of the electron supply layer.

Surface-stabilized semiconductor device

An LED comprising a light-generating semiconductor region having an active layer sandwiched between two confining layers of opposite conductivity types. A cathode is arranged centrally on one of the opposite major surfaces of the semiconductor region from which is emitted the light. An array of discrete gold regions are formed via transition metal regions on the other major surface of the semiconductor region at which is exposed one of the confining layers which is of n-type AlGaInP semiconductor material. The gold is thermally diffused into the confining layer via the transition metal regions at a temperature less than the eutectic point of gold and gallium, thereby creating an array of ohmic contact regions of alloyed or intermingled gold and gallium, which are less absorptive of light than their conventional counterparts, to a thickness of 20 to 1000 angstroms. After removing the transition metal regions and gold regions from the surface of the light-generating semiconductor region, a reflective layer of aluminum is formed so as to cover both the ohmic contact regions and the exposed surface portions of the AlGaInP confining layer. An electroconductive baseplate of doped silicon is then bonded to the reflective layer.

Gallium-containing light-emitting semiconductor device and method of fabrication

In a semiconductor light emitting element, multiple bosses having a cylindrical shape and dispersed like islands, and recesses are formed on the upper surface of a window layer. A contact electrode is formed on the upper surface of the bosses. A transparent dielectric film is formed in the recesses. A transparent conductor film is formed on the transparent dielectric film and the contact electrode.

Semiconductor light emitting element and fabrication method thereof

An LED comprises a semiconductor region including an active layer for generating light. An anode is arranged centrally on one of the opposite major surfaces of the semiconductor region from which is emitted the light. A reflective metal layer is bonded to the other major surface of the light-generating semiconductor region via an ohmic contact layer. Sufficiently thin to permit the passage of light therethrough, the ohmic contact layer is formed in an open-worked pattern to leave exposed part of the second major surface of the semiconductor region. A transparent, open-worked anti-alloying layer is interposed between the light-generating semiconductor region and the reflective metal layer, covering that part of the second major surface of the light-generating semiconductor region which is left exposed by the ohmic contact layer. The anti-alloying layer prevents the light-generating semiconductor region and reflective metal layer from alloying during heat treatments conducted in the curse of LED manufacture. A greater percentage of the light from the light-generating semiconductor region is reflected by the reflective metal layer for emission from the first major surface of the light-generating semiconductor region than in the absence of the anti-alloying layer.

Light-emitting semiconductor device of improved efficiency

A semiconductor light-emitting device includes substrate (), a plurality of light-emitting-element-layers (. . . ) of semiconductor material formed on the substrate () so as to be isolated from each other and having a wider band gap than the substrate (), and phosphors (. . . ) converting wavelengths of light from the light-emitting-element-layers (. . . ) into other wavelengths.

Semiconductor light-emitting device using phosphors for performing wavelength conversion

A light emitting diode has a semiconductor region for production of light. The semiconductor region is a lamination of two complementary layers, an n-type semiconductor layer, an active layer, a p-type semiconductor layer, another complementary layer, and an ohmic contact layer, in that order from a first major surface of the semiconductor layer, from which the light is emitted, toward a second. A reflective metal layer covers the second major surface of the semiconductor region via a transparent layer for reflecting the light that has traveled through the transparent layer from the semiconductor region. The transparent layer serves to prevent the semiconductor region and the reflective layer from alloying by heat treatments during the manufacture of the LED.

Light-emitting semiconductor device and method of fabrication

An LED is disclosed which has a laminated semiconductor body with an anode and a cathode formed on a pair of opposite faces thereof. Among the layers of the semiconductor body are an active layer of AlGaInP semiconductor material, an n type cladding layer of either n type AlGaInP or n type AlInP semiconductor material on one side of the active layer, and a p type cladding layer of p type AlGaInP or p type AlInP semiconductor material on another side of the active layer. Unlike the conventional belief that the active layer should be as free as possible from the infiltration of Zn used in the p type cladding layer as an impurity to determine its p conductivity type, and hence as high in crystallinity as possible, Zn is positively doped into the active layer with a concentration of 1.times.10.sup.16 -5.times.10.sup.17 cm.sup.-3.

Growing community of inventors

Niiza, Japan

Hitoshi Murofushi