Abstract: A nitride semiconductor light-emitting element includes a light-emitting layer comprising a well layer comprising AlGaN and emitting ultraviolet light; an electron blocking layer being located on the light-emitting layer and comprising AlGaN with a first Al composition ratio higher than an Al composition ratio of the well layer; and a p-type cladding layer being located on the electron blocking layer, comprising AlGaN with a second Al composition ratio higher than the Al composition ratio of the well layer and lower than the first Al composition ratio, and being doped with a predetermined concentration of a p-type dopant. An interface between the electron blocking layer and the p-type cladding layer is doped with not less than a predetermined amount of an n-type dopant.

Abstract: A gas sensor 1 according to the present invention includes: a gas sensor element 22; a box-like casing 3 having a wall portion 3B1 provided with a gas introduction port 3B2; a circuit board 4 having a mounting surface 4a on which the gas sensor element 22 is mounted, and disposed inside the casing 3 such that the mounting surface 4a is away from the wall portion 3B1 and the gas sensor element 22 overlaps with the gas introduction port 3B2; and an annular elastic seal body 5 formed on the mounting surface 4a so as to surround the gas sensor element 22, and disposed between the mounting surface 4a and the wall portion 3B1. The elastic seal body 5 is made of sulfur-free condensation silicone resin.

Abstract: A nitride semiconductor light-emitting element emits ultraviolet light at a central wavelength of more than 320 nm and not more than 365 nm. The nitride semiconductor light-emitting element includes a substrate having a c-plane as a growth surface and a nitride semiconductor layer stacked on the growth surface of the substrate. The nitride semiconductor layer includes an n-type semiconductor layer, and an active layer being formed on the n-type semiconductor layer on the opposite side to the substrate and comprising a single quantum well structure with one well layer. The n-type semiconductor layer has an Al composition ratio of not more than 50% and a film thickness of more than 2 ?m. A composition difference obtained by subtracting an Al composition ratio of the well layer from the Al composition ratio of the n-type semiconductor layer is not less than 22%.

Abstract: A nitride semiconductor light-emitting element includes a light-emitting layer comprising a well layer comprising AlGaN and emitting ultraviolet light; an electron blocking layer being located on the light-emitting layer and comprising AlGaN with a first Al composition ratio higher than an Al composition ratio of the well layer; and a p-type cladding layer being located on the electron blocking layer, comprising AlGaN with a second Al composition ratio higher than the Al composition ratio of the well layer and lower than the first Al composition ratio, and being doped with a predetermined concentration of a p-type dopant. An interface between the electron blocking layer and the p-type cladding layer is doped with not less than a predetermined amount of an n-type dopant.

Abstract: A method for manufacturing a nitride semiconductor light-emitting element includes growing a p-type cladding layer with an average Al composition ratio in a thickness direction of not less than 70%, and growing a p-type contact layer with an Al composition ratio of not more than 10%. A flow rate ratio Fp/FIII is a p/III ratio and a flow rate ratio FV/FIII is a V/III ratio. The p-type cladding layer is grown in the growing the p-type cladding layer at a growth rate of not more than 2.5 nm/min, a p/III ratio of not less than 0.0002 and not more than 0.0400 and a VIII ratio of not more than 7000. The p-type contact layer is grown in the growing the p-type contact layer at a growth rate of not more than 3.3 nm/min, a p/III ratio of not less than 0.0200 and a V/III ratio of not less than 10000.

Abstract: A nitride semiconductor light-emitting element includes an n-type semiconductor layer; a p-type semiconductor layer; an active layer provided between the n-type semiconductor layer and the p-type semiconductor layer; and an electron blocking layer provided between the active layer and the p-type semiconductor layer. At least one of the p-type semiconductor layer and the electron blocking layer includes an oxygen-containing portion including oxygen. An oxygen concentration at each position of the oxygen-containing portion in a stacking direction of the n-type semiconductor layer, the active layer, the electron blocking layer and the p-type semiconductor layer is not less than 2.5×1016 atoms/cm3.

Abstract: A nitride semiconductor light-emitting element includes an n-type semiconductor layer; a p-type semiconductor layer; an active layer provided between the n-type semiconductor layer and the p-type semiconductor layer; and an electron blocking layer provided between the active layer and the p-type semiconductor layer. A film thickness of the electron blocking layer is not more than 100 nm. An average value of a hydrogen concentration over the electron blocking layer in a stacking direction of the n-type semiconductor layer, the active layer, the electron blocking layer and the p-type semiconductor layer is not more than 2.0×1018 atoms/cm3. A boundary portion between the p-type semiconductor layer and the electron blocking layer includes an n-type impurity.

Abstract: A nitride semiconductor light-emitting element includes an n-type cladding layer including n-type AlGaN, and a multiple quantum well layer including a barrier layer that includes AlGaN and is located on the n-type cladding layer side, wherein the nitride semiconductor light-emitting element further comprises a trigger layer that is located between the n-type cladding layer and the barrier layer and comprises Si, wherein a plural V-pits starting from dislocations in the n-type cladding layer and ending in the multiple quantum well are formed in the n-type cladding layer and the multiple quantum well layer.

Abstract: A nitride semiconductor light-emitting element includes an active layer comprising at least one well layer, a p-type semiconductor layer located on one side of the active layer, and an electron blocking stack body located between the active layer and the p-type semiconductor layer. The electron blocking stack body includes a first electron blocking layer and a second electron blocking layer that is located on the p-type semiconductor layer side relative to the first electron blocking layer and has a lower Al composition ratio than that of the first electron blocking layer. When a total number of the well layers in the active layer is N, a film thickness of the first electron blocking layer is a film thickness d [nm] and an Al composition ratio of the second electron blocking layer is an Al composition ratio x [%], relationships 0.1N+0.9?d?0.2N+2.0 and 10N+40?x?10N+60 are satisfied.

Abstract: A nitride semiconductor light-emitting element includes a first semiconductor layer; an active layer provided on the first semiconductor layer on one side; a second semiconductor layer provided on the active layer on the opposite side to the first semiconductor layer so as to be in contact with the active layer; and a reflective electrode provided on the second semiconductor layer on the opposite side to the active layer so as to be in contact with the second semiconductor layer and reflects light emitted from the active layer. When an optical film thickness of the second semiconductor layer is an optical film thickness L [nm], a central wavelength of the light emitted from the active layer is a wavelength ? [nm], and an arbitrary number between 1 and 2 is a value m, a relationship 0.48 m ??L?0.5 m ?+(?0.05 m+0.3)? is satisfied.

Abstract: A nitride semiconductor light-emitting element includes an n-type cladding layer including n-type AlGaN, and an active layer that includes AlGaN and is located on the n-type cladding layer. Si concentration distribution in a direction of stacking the n-type cladding layer and the active layer has a local peak in the active layer.

Abstract: A nitride semiconductor light-emitting element includes an n-type cladding layer including n-type AlGaN and having a first Al composition ratio, and a multiple quantum well layer in which a plurality (number N) of barrier layers including AlGaN having a second Al composition ratio more than the first Al composition ratio and a plural (number N) well layers having an Al composition ratio less than the second Al composition ratio are stacked alternately in this order, wherein the second Al composition ratio of the plurality of barrier layers of the multiple quantum well layer increases at a predetermined increase rate from an n-type cladding layer side toward an opposite side to the n-type cladding layer side.

Abstract: A gas sensor (1) including a first gas detection element (2) and a second gas detection element (3), a first storage portion (4) having a first internal space (4A), and a first opening (4B) establishing communication between the first internal space (4A) and the outside space thereof exposed to a detection subject atmosphere, a second storage portion (5) having a second internal space (5A) and a second opening (5B) establishing communication between the second internal space (5A) and the outside space, a first membrane (4C) allowing permeation of water vapor and substantially not allowing permeation of a detection target gas, and covering the first opening (4B), and a calculation unit (12) for calculating the concentration of a detection target gas contained in the detection subject atmosphere, based on outputs from the first and second gas detection elements (2, 3), respectively.

Abstract: A nitride semiconductor light-emitting element includes an active layer including an AlGaN-based barrier layer, a p-type contact layer located on an upper side of the active layer, and an electron blocking stack body located between the active layer and the p-type contact layer. The electron blocking stack body includes a first electron blocking layer and a second electron blocking layer. The first electron blocking layer is located on the active layer side and has a higher Al composition ratio than an Al composition ratio in the barrier layer. The second electron blocking layer is located on the p-type contact layer side and has a lower Al composition ratio than an Al composition ratio in the barrier layer.

Abstract: A nitride semiconductor light emitting element includes a multi-quantum well layer including AlGaN, and including a plurality of well layers and producing light by combining carriers and emitting deep ultraviolet light with a central wavelength of 250 nm to 350 nm, a metal electrode part including Al that is located above the multi-quantum well layer and reflects a first light that is a part of the light produced by the multi-quantum well layer and travels upward, a multi-stacked semiconductor layer that is located between the multi-quantum well layer and the metal electrode part, includes a plurality of p-type semiconductor layers including p-type AlGaN, and is configured in such a manner that the first light travels out and back therewithin via reflection at the metal electrode part until meeting a second light that is a part of the light produced by the multi-quantum well layer and travels downward, and an ITO contact electrode part provided between the metal electrode part and the multi-quantum well layer

Abstract: A nitride semiconductor light-emitting element includes a substrate, a buffer layer formed on the substrate, an n-type semiconductor layer formed on the buffer layer, and an active layer being formed on the n-type semiconductor layer and comprising a single quantum well structure. A full width at half maximum of an X-ray rocking curve for a (102) plane of the buffer layer is not less than 369.4 arcsec and not more than 492.5 arcsec.

Abstract: A nitride semiconductor light-emitting element includes an active layer that emits ultraviolet light, a p-type AlGaN-based electron blocking stack body that is located on the active layer and has a structure formed by sequentially stacking a first electron blocking layer, a second electron blocking layer and a third electron blocking layer from the active layer side, and a p-type contact layer located on the electron blocking stack body. An Al composition ratio in the second electron blocking layer is lower than an Al composition ratio in the first electron blocking layer, and an Al composition ratio in the third electron blocking layer decreases from the second electron blocking layer side toward the p-type contact layer side.

Abstract: A nitride semiconductor light-emitting element includes an n-type semiconductor layer, a p-type semiconductor layer, an active layer provided between the n-type semiconductor layer and the p-type semiconductor layer, and an electron blocking layer comprising Al and being provided between the active layer and the p-type semiconductor layer. The electron blocking layer partially includes a high Al composition portion in at least one cross section orthogonal to a stacking direction, the high Al composition portion having an Al composition ratio higher than a surrounding portion.

Abstract: A nitride semiconductor light-emitting element includes an n-type semiconductor layer, a p-type semiconductor layer, an active layer, and an electron blocking layer comprising at least one layer. The at least one layer of the electron blocking layer includes a peak-containing layer having an n-type impurity concentration peak in an n-type impurity concentration distribution along a stacking direction. The n-type impurity concentration peak appears as a local maximum in the n-type impurity concentration distribution along the stacking direction in the peak-containing layer and has an n-type impurity concentration of not less than 10 times a smallest value of the n-type impurity concentration in a region along the stacking direction between positions that are separated from a position of the peak in the stacking direction on both sides in the stacking direction by 10% of a thickness of the peak-containing layer.

Abstract: A nitride semiconductor light-emitting element outputs ultraviolet light. The nitride semiconductor light-emitting element includes an active layer including a quantum well structure that generates the ultraviolet light, a dislocation suppression structure-containing layer being formed on the active layer and including a dislocation suppression structure that stops or bends a dislocation from the active layer; and a p-type contact layer being formed on the dislocation suppression structure-containing layer and having a thickness of not less than 10 nm and not more than 30 nm.