Showa Denko K.k.

Showa Denko Kabushiki Kaisha

Ryouichi Takeuchi

Hiroshi Suzuki

Wataru Nabekura

Takashi Udagawa

Atsushi Matsumura

Noriyoshi Seo

Takashi Watanabe

Hironori Ara

Noritaka Muraki

Noriyuki Aihara

Kazuhiro Mitani

Takaharu Hoshina

Keiichi Matsuzawa

Kyousuke Masuya

Junichi Yamazaki

Toshiki Yoshiuji

A plant-cultivating method is provided which comprises a red light irradiation step (A) and a blue light irradiation step (B), wherein the step (A) and the step (B) are independently carried out for a predetermined period of time under cultivation conditions such that the concentration of carbon dioxide in a cultivation atmosphere at the step (B) is higher than that at the step (A). Preferably the concentrations of carbon dioxide at the step (B) and the step (A) are 1000-2500 ppm and 700-1500 ppm, respectively. The concentration of carbon dioxide at the step (B) is preferably at least 200 ppm higher than that at the step (A).

Method for cultivating plant

The present invention relates to an epitaxial wafer for a light-emitting diode wherein the peak emission wavelength is 655 nm or more, and it is possible to improve reliability. The epitaxial wafer for light-emitting diodes includes a GaAs substrate () and a pn-junction type light-emitting unit () provided on the GaAs substrate (), wherein light-emitting unit () is formed as a multilayer structure in which a strained light-emitting layer and a barrier layer are alternately stacked, and the composition formula of the barrier layer is (AlGa)InP (0.3&#x2266;X&#x2266;0.7, 0.51&#x2266;Y&#x2266;0.54).

Epitaxial wafer for light-emitting diodes

A plant-cultivating method is provided which comprises a step (A) of irradiating a plant with a red light and a step (B) of irradiating a plant with a blue light, and a step (C) of irradiating a plant with a light predominantly comprised of far-red light wherein the step (A), the step (B) and the step (C) are independently and separately carried out for a predetermined period of time. The light irradiated at each of the steps (A), (B) and (C) has at least 60%, based on the total emission intensity of the light, of an emission intensity ratio of red light, blue light or far-red light.

A multicolor light emitting diode lamp includes a blue LED and a AlGaInP-based red LED having high luminescence efficiency, balancing with the blue LED are mounted in the same package. The red LED includes a light emitting section including a light emitting layer having a composition formula, (AlGa)InP (0&#x2266;X&#x2266;1 and 0&#x3c;Y&#x2266;1). The red LED emits at least as many photons as the blue LED when the same electric current is flowed. When a strong red light is desirable for plant growth, by mounting two red LEDs and one blue LED, a desired mixed color is obtained with one lamp, and irradiation of light can be made uniform.

Multicolor light emitting diode lamp for plant growth, illumination apparatus, and plant growth method

A plant-cultivating method is provided which comprises a step (A) of irradiating a plant with a red light and a step (B) of irradiating a plant with a blue light, wherein the step (A) and the step (B) are independently carried out for a predetermined period of time under cultivation conditions such that a fertilizer is used for each of the step (A) and the step (B), of which at least the fertilizer used for the step (A) is applied in the form of a nutritious liquid containing fertilizer ingredients and further carbon dioxide added therein. Preferably, a nutritious liquid is applied at each of the step (A) and the step (B), and the nutritious liquid applied at the step (A) contains carbon dioxide at a concentration higher than that in the nutritious liquid applied at the step (B).

A plant-cultivating method is provided which comprises a red light irradiation step (A) and a blue light irradiation step (B), wherein the step (A) and the step (B) are independently carried out for a predetermined period of time under cultivation conditions such that a fertilizer is used at each of the step (A) and the step (B), of which at least the fertilizer used at the step (B) is applied in the form of a nutritious liquid containing fertilizer ingredients and further an increased amount of dissolved oxygen, which nutritious liquid is prepared by adding oxygen therein. Preferably, a nutritious liquid is applied at each of the step (A) and the step (B), and the nutritious liquid applied at the step (B) contains dissolved oxygen at a content higher than that in the nutritious liquid applied at the step (A).

A light emitting diode is provided by the present invention which includes a pn junction-type light emitting unit having a light emitting layer () composed of n layers of a strained light emitting layer () and n&#x2212;1 layers of a barrier layer (), wherein when a barrier layer exists, the light emitting layer () has a structure in which one strained light emitting layer () and one barrier layer () are laminated alternately, n represents an integer of 1 to 7, and the thickness of the light emitting layer () is not more than 250 nm.

Light emitting diode and light emitting diode lamp

Disclosed is a light-emitting diode, which has a red and infrared emitting wavelength, excellent monochromatism characteristics, and high output and high efficiency and excellent humidity resistance. The light-emitting diode is provided with: a light-emitting section, which includes an active layer having a quantum well structure and formed by laminating alternately a well layer which comprises a composition expressed by the composition formula of (AlGa)As (0&#x2266;X1&#x2266;1) and a barrier layer which comprises a composition expressed by the composition formula of (AlGa)As (0&#x3c;X2&#x2266;1), and a first clad layer and a second clad layer, between both of which the active layer is sandwiched, wherein the first clad layer and the second clad layer comprise a composition expressed by the composition formula of (AlGa)InP (0&#x2266;X3&#x2266;1, 0&#x3c;Y1&#x2266;1); a current diffusion layer formed on the light-emitting section; and a functional substrate bonded to the current diffusion layer.

Light emitting diode, light emitting diode lamp, and illuminating apparatus

A light emitting diode including a compound semiconductor layer having at least a pn junction-type light emitting unit and a strain adjustment layer stacked on the light emitting unit, wherein the light emitting unit has a stacked structure containing a strained light emitting layer having a composition formula of (AlGa)InP (wherein X and Y are numerical values that satisfy 0&#x2266;X&#x2266;0.1 and 0.39&#x2266;Y&#x2266;0.45 respectively) and a barrier layer, and the strain adjustment layer is transparent to the emission wavelength and has a lattice constant that is smaller than the lattice constants of the strained light emitting layer and the barrier layer. The light emitting diode has an emission wavelength of not less than 655 nm, exhibits excellent monochromaticity, high output and/or high efficiency, and has a fast response speed.

Light emitting diode, light emitting diode lamp and illuminating device

The present invention provides a light-emitting diode that includes two electrodes provided on a light-emitting surface, and exhibits high light extraction efficiency and high-brightness. The present invention relates to a light-emitting diode () including: a compound semiconductor layer () including a light-emitting portion () containing a light-emitting layer (); and a transparent substrate (), wherein the compound semiconductor layer () and the transparent substrate () are bonded, and a first electrode () and a second electrode () are provided on the side of a main light-emitting surface () of the compound semiconductor layer (), wherein the transparent substrate () includes: an upper surface (A) bonding to the compound semiconductor layer (); a bottom surface (B) having smaller dimensions than dimensions of the upper surface (A); and a side surface including at least inclined surface () inclined from the side of the upper surface toward the side of the bottom surface, wherein the first and second electrodes () and () are disposed within a region in which the bottom surface (B) is projected when viewed from the top of the light-emitting diode.

Light-emitting diode, method for manufacturing the same, and light-emitting diode lamp

Disclosed is a light-emitting diode, which has a red and infrared emitting wavelength, excellent monochromatism characteristics, and high output and high efficiency and excellent humidity resistance. The light-emitting diode is provided with: a light-emitting section, which includes an active layer having a quantum well structure and formed by laminating alternately a well layer which comprises a composition expressed by the composition formula of (AlGa) As (0&#x2266;X&#x2266;1) and a barrier layer which comprises a composition expressed by the composition formula of (AlGa) As (0&#x3c;2&#x2266;1), and a first clad layer and a second clad layer, between both of which the active layer is sandwiched, wherein the first clad layer and the second clad layer comprise a composition expressed by the composition formula of (AlGa)InP (0&#x2266;X&#x2266;1, 0&#x3c;Y&#x2266;1); a current diffusion layer formed on the light-emitting section; and a functional substrate bonded to the current diffusion layer.

A light-emitting diode having a high output, high efficiency, and a long service life under a high-humidity environment is provided. The light-emitting diode () includes a compound semiconductor layer () having a light-emitting section (), ohmic electrodes () provided on the main light extraction surface of the compound semiconductor layer (), and an electrode protection layer () for protecting the ohmic electrodes (), wherein the Al concentrations of the surfaces () of the compound semiconductor layer (), which include the main light extraction surface, are 20% or less and the As concentration of the surfaces () is less than 1%, and the electrode protection layer () has a two-layer structure composed of a first protective film () provided so as to cover the ohmic electrodes () and a second protective film () provided so as to cover at least an end portion of the first protective film ().

Light emitting diode, light emitting diode lamp, and lighting apparatus

An epitaxial wafer for a light emitting diode, including a GaAs substrate, a light emitting unit provided on the GaAs substrate, and a strain adjustment layer provided on the light emitting unit, wherein the light emitting unit has a strained light emitting layer having a composition formula of (AlGa)InP (wherein X and Y are numerical values that satisfy 0&#x2266;X&#x2266;0.1 and 0.39&#x2266;Y&#x2266;0.45 respectively), and the strain adjustment layer is transparent to the emission wavelength and has a lattice constant that is smaller than the lattice constant of the GaAs substrate. The invention provides an epitaxial wafer that enables mass production of a high-output and/or high-efficiency LED having an emission wavelength of not less than 655 nm.

Epitaxial wafer for light emitting diode

A compound semiconductor light-emitting diode includes a light-emitting layer () formed of aluminum-gallium-indium phosphide, a light-emitting part () having component layers individually formed of a Group III-V compound semiconductor, a transparent supporting layer () bonded to one of the outermost surface layers () of the light-emitting part () and transparent to the light emitted from the light-emitting layer (), and a bonding layer () formed between the supporting layer () and the one of the outermost surface layers () of the light-emitting part () containing oxygen atoms at a concentration of 1&#xd7;10cmor less.

Compound semiconductor light-emitting diode and method for fabrication thereof

A light-emitting diode includes a substrate, a compound semiconductor layer including a p-n junction-type light-emitting part formed on the substrate, an electric conductor disposed on the compound semiconductor layer and formed of an electrically conductive material optically transparent to the light emitted from the light-emitting part and a high resistance layer possessing higher resistance than the electric conductor and provided in the middle between the compound semiconductor layer and the electric conductor. In the configuration of a light-emitting diode lamp, the electric conductor and the electrode disposed on the semiconductor layer on the side opposite to the electric conductor across the light-emitting layer are made to assume an equal electric potential by means of wire bonding. The light-emitting diode abounds in luminance and excels in electrostatic breakdown voltage.

Growing community of inventors

Chichibu, Japan

Ryouichi Takeuchi