Abstract: A gas concentration measurement system includes a limiting current-type gas sensor, a voltage source connected to the limiting current-type gas sensor, a current detector connected to the limiting current-type gas sensor, and a gas concentration arithmetic unit connected to the current detector. The voltage source supplies first and second voltages to the limiting current-type gas sensor. The first and second voltages generate first and second limiting currents corresponding to first and second gases, respectively, in the limiting current-type gas sensor. The current detector acquires first and second limiting current values of the limiting current-type gas sensor when the first and second voltages are applied to the limiting current-type gas sensor, respectively.

Abstract: A nitrogen oxide based gas sensor includes: a substrate provided with a beam structure having a MEMS structure; a heater disposed on the substrate; a lower electrode disposed on the heater, a solid electrolyte layer disposed on the lower electrode; an upper electrode disposed on a surface of the solid electrolyte layer facing the lower electrode and configured to introduce a measurement target gas; a cavity portion formed in the substrate; and a gas flow path disposed so as to connect the cavity portion and the lower electrode, wherein the gas sensor is configured to detect a concentration of nitrogen oxide in the measurement target gas.

Abstract: The limiting-current type gas sensor includes: a porous lower electrode disposed on a substrate; an insulating film disposed on the porous lower electrode; a solid electrolyte layer disposed on the porous lower electrode in an opening formed by patterning the insulating film, and further disposed on the insulating film surrounding the opening; and a porous upper electrode disposed on the solid electrolyte layer, wherein the insulating film realizes non-contact between an edge face of the solid electrolyte layer and the porous lower electrode, in order to suppress the intake of oxygen (O) ion from the edge face of the solid electrolyte layer, and thereby the surface-conduction current component between the porous upper electrode and the porous lower electrode can be reduced. There can be provided the limiting-current type gas sensor capable of reducing the surface-conduction current component and realizing low power consumption.

Abstract: A nitrogen oxide based gas sensor includes: a substrate provided with a beam structure having a MEMS structure; a heater disposed on the substrate; a lower electrode disposed on the heater, a solid electrolyte layer disposed on the lower electrode; an upper electrode disposed on a surface of the solid electrolyte layer facing the lower electrode and configured to introduce a measurement target gas; a cavity portion formed in the substrate; and a gas flow path disposed so as to connect the cavity portion and the lower electrode, wherein the gas sensor is configured to detect a concentration of nitrogen oxide in the measurement target gas.

Abstract: A semiconductor type gas sensor for detecting a CO2 gas includes: a gas-sensitive body in which a surface of a tin oxide is coated with a thin film of a rare earth oxide; a pair of positive and negative electrodes tightly formed on the gas-sensitive body; and a micro-heater configured to heat the gas-sensitive body.

Abstract: The limiting-current type gas sensor includes: a porous lower electrode disposed on a substrate; an insulating film disposed on the porous lower electrode; a solid electrolyte layer disposed on the porous lower electrode in an opening formed by patterning the insulating film, and further disposed on the insulating film surrounding the opening; and a porous upper electrode disposed on the solid electrolyte layer, wherein the insulating film realizes non-contact between an edge face of the solid electrolyte layer and the porous lower electrode, in order to suppress the intake of oxygen (O) ion from the edge face of the solid electrolyte layer, and thereby the surface-conduction current component between the porous upper electrode and the porous lower electrode can be reduced. There can be provided the limiting-current type gas sensor capable of reducing the surface-conduction current component and realizing low power consumption.

Abstract: To provide both a photodetecting element and a photodetecting device which can prevent generating of a plurality of current paths, and can detect with stability and high sensitivity regardless of a surface state instability of an optical absorption layer. The photodetecting element includes an optically transparent substrate, an optical absorption layer, an electrode, an electrode, an adhesive layer, an insulating film, and a package. The optical absorption layer is formed on the optically transparent substrate, and a part of each the electrodes is embedded in the optical absorption layer. The photodetecting unit is bonded junction down with the adhesive layer on the package. The optical absorption layer absorbs light of a specified wavelength selectively to be converted into an electric signal. The light to be measured is irradiated from a back side surface of the optically transparent substrate.

Abstract: A limiting-current type gas sensor includes: an Si substrate (1); a micro heater (2) formed on the Si substrate (1); a solid electrolyte layer (4) having ion conductivity formed on the Si substrate (1); a pair of positive and negative porous electrodes (5a, 5b) adhesively formed on the solid electrolyte layer (4); and a detection circuit (8) configured to detect predetermined gas density in measured gas with a limiting current method by applying voltage between the pair of the positive and negative porous electrodes (5a, 5b). There are provided the limiting-current type gas sensor which can reduce power consumption, a fabrication method of such a limiting-current type gas sensor, and a sensor network system.

Abstract: Two light receiving elements are formed on a support substrate. A first light receiving element is formed of a p-type layer, an n-type layer, a light absorption semiconductor layer, an anode electrode, a cathode electrode, a protection film, etc. A second light receiving element is formed of a p-type layer, an n-type layer, a transmissive film, an anode electrode, a cathode electrode, a protection film, etc. The light absorption semiconductor layer absorbs light in a wavelength range ? and disposed closer to the light receiving surface than is the pn junction region. The transmissive film has no light absorption range and disposed closer to the light receiving surface than is the pn junction region. The amount of light in the wavelength range ? is measured through computation using a detection signal from the first light receiving element and a detection signal from the second light receiving element.

Abstract: A ZnO-based semiconductor device includes an n type ZnO-based semiconductor layer, an aluminum oxide film formed on the n type ZnO-based semiconductor layer, and a palladium layer formed on the aluminum oxide film. With this configuration, the n type ZnO-based semiconductor layer and the palladium layer form a Schottky barrier structure.

Abstract: Two light receiving elements are formed on a support substrate. A first light receiving element is formed of a p-type layer, an n-type layer, a light absorption semiconductor layer, an anode electrode, a cathode electrode, a protection film, etc. A second light receiving element is formed of a p-type layer, an n-type layer, a transmissive film, an anode electrode, a cathode electrode, a protection film, etc. The light absorption semiconductor layer absorbs light in a wavelength range ? and disposed closer to the light receiving surface than is the pn junction region. The transmissive film has no light absorption range and disposed closer to the light receiving surface than is the pn junction region. The amount of light in the wavelength range ? is measured through computation using a detection signal from the first light receiving element and a detection signal from the second light receiving element.

Abstract: Two light receiving elements are formed on a support substrate. A first light receiving element is formed of a p-type layer, an n-type layer, a light absorption semiconductor layer, an anode electrode, a cathode electrode, a protection film, etc. A second light receiving element is formed of a p-type layer, an n-type layer, a transmissive film, an anode electrode, a cathode electrode, a protection film, etc. The light absorption semiconductor layer absorbs light in a wavelength range ? and disposed closer to the light receiving surface than is the pn junction region. The transmissive film has no light absorption range and disposed closer to the light receiving surface than is the pn junction region. The amount of light in the wavelength range ? is measured through computation using a detection signal from the first light receiving element and a detection signal from the second light receiving element.

Abstract: A p-type MgxZn1-xO-based thin film (1) is formed on a substrate (2) made of a ZnO-based semiconductor. The p-type MgxZn1-xO-based thin film (1) is composed so that X as a ratio of Mg with respect to Zn therein can be 0?X<1, preferably 0?X?0.5. In the p-type MgZnO thin film (1), nitrogen as p-type impurities which become an acceptor is contained at a concentration of approximately 5.0×1018 cm?3 or more. The p-type MgZnO thin film (1) is composed so that n-type impurities made of a group IV element such as silicon that becomes a donor can have a concentration of approximately 1.0×1017 cm?3 or less. The p-type MgZnO thin film (1) is composed so that n-type impurities made of a group III element such as boron and aluminum which become a donor can have a concentration of approximately 1.0×1016 cm?3 or less.

Abstract: To provide both a photodetecting element and a photodetecting device which can prevent generating of a plurality of current paths, and can detect with stability and high sensitivity regardless of a surface state instability of an optical absorption layer. The photodetecting element includes an optically transparent substrate, an optical absorption layer, an electrode, an electrode, an adhesive layer, an insulating film, and a package. The optical absorption layer is formed on the optically transparent substrate, and a part of each the electrodes is embedded in the optical absorption layer. The photodetecting unit is bonded junction down with the adhesive layer on the package. The optical absorption layer absorbs light of a specified wavelength selectively to be converted into an electric signal. The light to be measured is irradiated from a back side surface of the optically transparent substrate.

Abstract: A ZnO-based semiconductor device includes an n type ZnO-based semiconductor layer, an aluminum oxide film formed on the n type ZnO-based semiconductor layer, and a palladium layer formed on the aluminum oxide film. With this configuration, the n type ZnO-based semiconductor layer and the palladium layer form a Schottky barrier structure.

Abstract: Provided are a ZnO-based thin film and a ZnO-based semiconductor device which allow: reduction in a burden on a manufacturing apparatus; improvement of controllability and reproducibility of doping; and obtaining p-type conduction without changing a crystalline structure. In order to be formed into a p-type ZnO-based thin film, a ZnO-based thin film is formed by employing as a basic structure a superlattice structure of a MgZnO/ZnO super lattice layer 3. This superlattice component is formed with a laminated structure which includes acceptor-doped MgZnO layers 3b and acceptor-doped ZnO layers 3a. Hence, it is possible to improve controllability and reproducibility of the doping, and to prevent a change in a crystalline structure due to a doping material.

Abstract: Two light receiving elements are formed on a support substrate. A first light receiving element is formed of a p-type layer, an n-type layer, a light absorption semiconductor layer, an anode electrode, a cathode electrode, a protection film, etc. A second light receiving element is formed of a p-type layer, an n-type layer, a transmissive film, an anode electrode, a cathode electrode, a protection film, etc. The light absorption semiconductor layer absorbs light in a wavelength range ? and disposed closer to the light receiving surface than is the pn junction region. The transmissive film has no light absorption range and disposed closer to the light receiving surface than is the pn junction region. The amount of light in the wavelength range ? is measured through computation using a detection signal from the first light receiving element and a detection signal from the second light receiving element.

Abstract: A semiconductor element includes a semiconductor layer mainly composed of MgxZn1-xO (0<=x<1), in which manganese contained in the semiconductor layer as impurities has a density of not more than 1×1016 cm?3.

Abstract: Provided are: a p-type MgZnO-based thin film that functions as a p-type; and a semiconductor light emitting device that includes the p-type MgZnO-based thin film. A p-type MgxZn1-xO-based thin film (1) is formed on a substrate (2) made of a ZnO-based semiconductor. The p-type MgxZn1-xO-based thin film (1) is composed so that X as a ratio of Mg with respect to Zn therein can be 0?X<1, preferably 0?X?0.5. In the p-type MgZnO thin film (1), nitrogen as p-type impurities which become an acceptor is contained at a concentration of approximately 5.0×1018 cm?3 or more. The p-type MgZnO thin film (1) is composed so that n-type impurities made of a group IV element such as silicon that becomes a donor can have a concentration of approximately 1.0×1017 cm?3 or less. The p-type MgZnO thin film (1) is composed so that n-type impurities made of a group III element such as boron and aluminum which become a donor can have a concentration of approximately 1.0×1016 cm?3 or less.

Abstract: Provided is a ZnO-based semiconductor device in which, in the case of forming a laminate including an acceptor-doped layer made of a ZnO-based semiconductor, the properties of a film can be stabilized by preventing deterioration of the flatness of the acceptor-doped layer or a layer after the acceptor-doped layer and an increase of crystal defect in the layer, without lowering the concentration of an acceptor element.