Abstract: There is provided an electrochemical sensor, comprising: a working electrode; a counter electrode; and a base material supporting the working electrode and the counter electrode, wherein the working electrode is a chip-shaped electrode including a diamond film that causes a redox reaction on its surface when a predetermined voltage is applied in a state where a test sample exists between the working electrode and the counter electrode, and a support that comprises a material other than diamond and supports the diamond film, and the working electrode is mounted on the base material, with the support positioned on the base material side and at least a part of a side surface of the support exposed.

Abstract: An electrochemical sensor unit including: a working electrode; and a counter electrode, wherein the working electrode includes a diamond film which generates a redox reaction on a surface when a voltage is applied between the working electrode and the counter electrode, and a support which is formed of a material different from diamond and supports the diamond film, when the working electrode is viewed laterally, in the support, a width of a surface opposite to a surface in contact with the diamond film is smaller than a width of the diamond film, and a liquid test sample is supplied to the working electrode from the diamond film side.

Abstract: Disclosed herein is a light emitting diode (LED) including: a gallium nitride substrate; a gallium nitride-based first contact layer disposed on the gallium nitride substrate; a gallium nitride-based second contact layer; an active layer having a multi-quantum well structure and disposed between the first and second contact layers; and a super-lattice layer having a multilayer structure and disposed between the first contact layer and the active layer. By employing the gallium nitride substrate, the crystallinity of the semiconductor layers can be improved, and in addition, by disposing the super-lattice layer between the first contact layer and the active layer, a crystal defect that may be generated in the active layer can be prevented.

Abstract: To provide a high-quality nitride semiconductor ensuring high emission efficiency of a light-emitting element fabricated. In the present invention, when obtaining a nitride semiconductor by sequentially stacking a one conductivity type nitride semiconductor part, a quantum well active layer structure part, and a another conductivity type nitride semiconductor part opposite the one conductivity type, the crystal is grown on a base having a nonpolar principal nitride surface, the one conductivity type nitride semiconductor part is formed by sequentially stacking a first nitride semiconductor layer and a second nitride semiconductor layer, and the second nitride semiconductor layer has a thickness of 400 nm to 20 ?m and has a nonpolar outermost surface. By virtue of selecting the above-described base for crystal growth, an electron and a hole, which are contributing to light emission, can be prevented from spatial separation based on the QCSE effect and efficient radiation is realized.

Abstract: Disclosed herein are a high efficiency light emitting diode and a method of fabricating the same. The light emitting diode includes a semiconductor stacked structure disposed on the support substrate and including a gallium nitride-based p-type semiconductor layer, a gallium nitride-based active layer, and a gallium nitride-based n-type semiconductor layer; and a reflecting layer disposed between the support substrate and the semiconductor stacked structure, wherein the semiconductor stacked structure includes a plurality of protrusions having a truncated cone shape and fine cones formed on top surfaces of the protrusions. By this configuration, light extraction efficiency of the semiconductor stacked structure having low dislocation density can be improved.

Abstract: To provide a high-quality nitride semiconductor ensuring high emission efficiency of a light-emitting element fabricated. In the present invention, when obtaining a nitride semiconductor by sequentially stacking a one conductivity type nitride semiconductor part, a quantum well active layer structure part, and a another conductivity type nitride semiconductor part opposite the one conductivity type, the crystal is grown on a base having a nonpolar principal nitride surface, the one conductivity type nitride semiconductor part is formed by sequentially stacking a first nitride semiconductor layer and a second nitride semiconductor layer, and the second nitride semiconductor layer has a thickness of 400 nm to 20 ?m and has a nonpolar outermost surface. By virtue of selecting the above-described base for crystal growth, an electron and a hole, which are contributing to light emission, can be prevented from spatial separation based on the QCSE effect and efficient radiation is realized.

Abstract: A base at least one principal plane of which is a nitride is prepared for use in epitaxial growth. The base is placed on a susceptor in an epitaxial growth reactor and heated to a predetermined temperature (step A). The heating is started with inactive, nitrogen gas being supplied into the reactor. Then, active, NH3 gas is supplied. Then, a growth step (step B) of a first nitride semiconductor layer is started without an intervening step of thermally cleaning the principal nitride plane of the base. In step B, the first nitride semiconductor layer is epitaxially grown on a principal nitride plane of a base without supply of an Si source material. Then, a relatively thick, second nitride semiconductor layer is epitaxially grown on the first nitride semiconductor layer by supplying an n-type dopant source material (step C).

Abstract: Provided is a novel method for producing an m-plane nitride-based LED, the method making it possible to obtain an m-plane nitride-based LED reduced in forward voltage. The method comprising (i) a step of forming an active layer consisting of a nitride semiconductor over an n-type nitride semiconductor layer in which an angle between the thickness direction and the m-axis of a hexagonal crystal is 10 degrees or less, (ii) a step of forming an AlGaN layer doped with a p-type impurity over the active layer, (iii) a step of forming a contact layer consisting of InGaN is formed on the surface of the AlGaN layer, and (iv) a step of forming an electrode on the surface of the contact layer.

Abstract: Disclosed herein is a light emitting diode (LED) including: a gallium nitride substrate; a gallium nitride-based first contact layer disposed on the gallium nitride substrate; a gallium nitride-based second contact layer; an active layer having a multi-quantum well structure and disposed between the first and second contact layers; and a super-lattice layer having a multilayer structure and disposed between the first contact layer and the active layer. By employing the gallium nitride substrate, the crystallinity of the semiconductor layers can be improved, and in addition, by disposing the super-lattice layer between the first contact layer and the active layer, a crystal defect that may be generated in the active layer can be prevented.

Abstract: Disclosed herein are a high efficiency light emitting diode and a method of fabricating the same. The light emitting diode includes a semiconductor stacked structure disposed on the support substrate and including a gallium nitride-based p-type semiconductor layer, a gallium nitride-based active layer, and a gallium nitride-based n-type semiconductor layer; and a reflecting layer disposed between the support substrate and the semiconductor stacked structure, wherein the semiconductor stacked structure includes a plurality of protrusions having a truncated cone shape and fine cones formed on top surfaces of the protrusions. By this configuration, light extraction efficiency of the semiconductor stacked structure having low dislocation density can be improved.

Abstract: A base at least one principal plane of which is a nitride is prepared for use in epitaxial growth. The base is placed on a susceptor in an epitaxial growth reactor and heated to a predetermined temperature (step A). The heating is started with inactive, nitrogen gas being supplied into the reactor. Then, active, NH3 gas is supplied. Then, a growth step (step B) of a first nitride semiconductor layer is started without an intervening step of thermally cleaning the principal nitride plane of the base. In step B, the first nitride semiconductor layer is epitaxially grown on a principal nitride plane of a base without supply of an Si source material. Then, a relatively thick, second nitride semiconductor layer is epitaxially grown on the first nitride semiconductor layer by supplying an n-type dopant source material (step C).

Abstract: To provide a high-quality nitride semiconductor ensuring high emission efficiency of a light-emitting element fabricated. In the present invention, when obtaining a nitride semiconductor by sequentially stacking a one conductivity type nitride semiconductor part, a quantum well active layer structure part, and a another conductivity type nitride semiconductor part opposite the one conductivity type, the crystal is grown on a base having a nonpolar principal nitride surface, the one conductivity type nitride semiconductor part is formed by sequentially stacking a first nitride semiconductor layer and a second nitride semiconductor layer, and the second nitride semiconductor layer has a thickness of 400 nm to 20 ?m and has a nonpolar outermost surface. By virtue of selecting the above-described base for crystal growth, an electron and a hole, which are contributing to light emission, can be prevented from spatial separation based on the QCSE effect and efficient radiation is realized.

Abstract: During the growth of a nitride semiconductor crystal on a nonpolar face nitride substrate, such as an m-face, the gas that constitutes the main flow in the process of heating up to a relatively high temperature range, before growth of the nitride semiconductor layer, (the atmosphere to which the main nitride face of the substrate is exposed) and the gas that constitutes the main flow until growth of first and second nitride semiconductor layers is completed (the atmosphere to which the main nitride face of the substrate is exposed) are primarily those that will not have an etching effect on the nitride, while no Si source is supplied at the beginning of growth of the nitride semiconductor layer. Therefore, nitrogen atoms are not desorbed from near the nitride surface of the epitaxial substrate, thus suppressing the introduction of defects into the epitaxial film. This also makes epitaxial growth possible with a surface morphology of excellent flatness.

Abstract: To provide a high-quality nitride semiconductor ensuring high emission efficiency of a light-emitting element fabricated. In the present invention, when obtaining a nitride semiconductor by sequentially stacking a one conductivity type nitride semiconductor part, a quantum well active layer structure part, and a another conductivity type nitride semiconductor part opposite the one conductivity type, the crystal is grown on a base having a nonpolar principal nitride surface, the one conductivity type nitride semiconductor part is formed by sequentially stacking a first nitride semiconductor layer and a second nitride semiconductor layer, and the second nitride semiconductor layer has a thickness of 400 nm to 20 ?m and has a nonpolar outermost surface. By virtue of selecting the above-described base for crystal growth, an electron and a hole, which are contributing to light emission, can be prevented from spatial separation based on the QCSE effect and efficient radiation is realized.

Abstract: To provide a high-quality nitride semiconductor ensuring high emission efficiency of a light-emitting element fabricated. In the present invention, when obtaining a nitride semiconductor by sequentially stacking a one conductivity type nitride semiconductor part, a quantum well active layer structure part, and a another conductivity type nitride semiconductor part opposite the one conductivity type, the crystal is grown on a base having a nonpolar principal nitride surface, the one conductivity type nitride semiconductor part is formed by sequentially stacking a first nitride semiconductor layer and a second nitride semiconductor layer, and the second nitride semiconductor layer has a thickness of 400 nm to 20 mm and has a nonpolar outermost surface. By virtue of selecting the above-described base for crystal growth, an electron and a hole, which are contributing to light emission, can be prevented from spatial separation based on the QCSE effect and efficient radiation is realized.

Abstract: A base at least one principal plane of which is a nitride is prepared for use in epitaxial growth. The base is placed on a susceptor in an epitaxial growth reactor and heated to a predetermined temperature (step A). The heating is started with inactive, nitrogen gas being supplied into the reactor. Then, active, NH3 gas is supplied. Then, a growth step (step B) of a first nitride semiconductor layer is started without an intervening step of thermally cleaning the principal nitride plane of the base. In step B, the first nitride semiconductor layer is epitaxially grown on a principal nitride plane of a base without supply of an Si source material. Then, a relatively thick, second nitride semiconductor layer is epitaxially grown on the first nitride semiconductor layer by supplying an n-type dopant source material (step C).

Abstract: During the growth of a nitride semiconductor crystal on a nonpolar face nitride substrate, such as an m-face, the gas that constitutes the main flow in the process of heating up to a relatively high temperature range, before growth of the nitride semiconductor layer, (the atmosphere to which the main nitride face of the substrate is exposed) and the gas that constitutes the main flow until growth of first and second nitride semiconductor layers is completed (the atmosphere to which the main nitride face of the substrate is exposed) are primarily those that will not have an etching effect on the nitride, while no Si source is supplied at the beginning of growth of the nitride semiconductor layer. Therefore, nitrogen atoms are not desorbed from near the nitride surface of the epitaxial substrate, thus suppressing the introduction of defects into the epitaxial film. This also makes epitaxial growth possible with a surface morphology of excellent flatness.

Abstract: III-V Compound semiconductor crystals characterized by containing Al and In as main constituent elements of group III, and also containing a constituent element of group V, and characterized in that the carbon concentration in the compound semiconductor crystals is 1×1016 cm?3 or higher, and the oxygen concentration therein is 1×1018 cm?3 or lower and is not higher than the carbon concentration; and a method for producing the III-V compound semiconductor crystals. By using the III-V compound semiconductor crystals, a semiconductor device showing satisfactory electric conductivity characteristics, and a semiconductor laser showing satisfactory high speed modulation characteristics can be provided.

Abstract: In order to control the polarization direction of laser light emitted by a vertical cavity surface emitting laser (VCSEL), the cross-sectional dimension of the p-DBR is so limited as to permit only a single fundamental transverse mode in a waveguide composed by the p-DBR. Some VCSEL-based devices are developed using arrays of VCSELs in which each VCSEL has a controlled direction of polarization.

Abstract: In order to control polarization direction of laser light emitted by a vertical cavity surface emitting laser (VCSEL), cross-sectional dimension of the p-DBR is so limited as to permit only a single fundamental transverse mode in a waveguide composed by the p-DBR. Some VCSEL-based devices are developed using arrays of VCSELs in which each VCSEL has a controlled direction of polarization.