Abstract: A semiconductor light-emitting element includes: an n-type clad layer of an n-type AlGaN-based semiconductor material; an active layer including a planarizing layer of an AlGaN-based semiconductor material provided on the n-type clad layer, a barrier layer of an AlGaN-based semiconductor material provided on the planarizing layer, and a well layer of an AlGaN-based semiconductor material provided on the barrier layer; and a p-type semiconductor layer provided on the active layer. The active layer emits deep ultraviolet light having a wavelength of 360 nm or shorter, and a ground level of a conduction band of the planarizing layer is lower than a ground level of a conduction band of the barrier layer and higher than a ground level of a conduction band of the well layer.

Abstract: A semiconductor light-emitting element includes: an n-type clad layer of an n-type AlGaN-based semiconductor material; an active layer including a planarizing layer of an AlGaN-based semiconductor material provided on the n-type clad layer, a barrier layer of an AlGaN-based semiconductor material provided on the planarizing layer, and a well layer of an AlGaN-based semiconductor material provided on the barrier layer; and a p-type semiconductor layer provided on the active layer. The active layer emits deep ultraviolet light having a wavelength of 360 nm or shorter, and a ground level of a conduction band of the planarizing layer is lower than a ground level of a conduction band of the barrier layer and higher than a ground level of a conduction band of the well layer.

Abstract: A semiconductor light-emitting element includes: an n-type clad layer of an n-type AlGaN-based semiconductor material; an active layer including a planarizing layer of an AlGaN-based semiconductor material provided on the n-type clad layer, a barrier layer of an AlGaN-based semiconductor material provided on the planarizing layer, and a well layer of an AlGaN-based semiconductor material provided on the barrier layer; and a p-type semiconductor layer provided on the active layer. The active layer emits deep ultraviolet light having a wavelength of 360 nm or shorter, and a ground level of a conduction band of the planarizing layer is lower than a ground level of a conduction band of the barrier layer and higher than a ground level of a conduction band of the well layer.

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 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 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 an n-type cladding layer including n-type AlGaN having a first Al composition ratio, a barrier layer including AlGaN that is located on the n-type cladding layer side in a multiple quantum well layer and has a second Al composition ratio greater than the first Al composition ratio, and a graded layer that is located between the n-type cladding layer and the barrier layer and has a third Al composition ratio that is between the first Al composition ratio and the second Al composition ratio, wherein the third Al composition ratio of the graded layer increases at a predetermined increase rate from the first Al composition ratio toward the second Al composition ratio.

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 1 contains an AlN layer 22 having a crystalline quality within a predetermined range and an n-type AlGaN formed atop the AlN layer 22 and having a predetermined Al composition ratio formed atop the AlN layer 22. In addition, as the crystalline quality falling within the predetermined range, the AlN layer 22 has a crystalline quality corresponding to an X-ray rocking curve half-width of 350 to 520 (arcsec vis-à-vis a (10-12) surface. As the predetermined Al composition ratio, the n-type AlGaN has an Al composition ratio of 40% to 70%.

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 nitride semiconductor light-emitting element includes an n-type cladding layer including n-type AlGaN having a first Al composition ratio, a barrier layer including AlGaN that is located on the n-type cladding layer side in a multiple quantum well layer and has a second Al composition ratio greater than the first Al composition ratio, and a graded layer that is located between the n-type cladding layer and the barrier layer and has a third Al composition ratio that is between the first Al composition ratio and the second Al composition ratio, wherein the third Al composition ratio of the graded layer increases at a predetermined increase rate from the first Al composition ratio toward the second Al composition ratio.

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 semiconductor light-emitting element includes: an n-type clad layer of an n-type AlGaN-based semiconductor material; an active layer including a planarizing layer of an AlGaN-based semiconductor material provided on the n-type clad layer, a barrier layer of an AlGaN-based semiconductor material provided on the planarizing layer, and a well layer of an AlGaN-based semiconductor material provided on the barrier layer; and a p-type semiconductor layer provided on the active layer. The active layer emits deep ultraviolet light having a wavelength of 360 nm or shorter, and a ground level of a conduction band of the planarizing layer is lower than a ground level of a conduction band of the barrier layer and higher than a ground level of a conduction band of the well layer.

Abstract: An exposure system is provided with an exposure head formed of a red organic EL element which emits light in a red region and another organic EL element which emits light in a predetermined wavelength range shorter than the red region. The exposure system exposes a color photosensitive body containing therein at least a red silver-salt photosensitive material sensitive to the light in the red region and another silver-salt photosensitive material sensitive to the light in the predetermined wavelength range. An optical filter cuts the wavelength components which are shorter than the predetermined wavelength range and included in a sensitive range of the red silver-salt photosensitive material.

Abstract: An endocavity ultrasonic probe includes a backing member of cylindrical or convex shape, and a plurality of strip shaped ultrasonic transducers arranged on the backing member. The ultrasonic transducer is composed of three piezoelectric layers, electrode layers formed above and below each piezoelectric layer, insulating films formed at one side face of each electrode layer, and side electrodes formed along both side faces of the piezoelectric layers and the electrode layers. The electrode layers are electrically connected to one of the side electrodes but insulated from the other side electrode. Two vertically adjacent electrode layers are electrically connected to a different one of the side electrodes.

Abstract: A semiconductor laser device having an active region including alternating layers of at least one quantum well layer and a plurality of barrier layers, where two of the plurality of barrier layers are the outermost layers of the alternating layers. Each of the at least one quantum well layer has a compressive strain, and each of the plurality of barrier layers has a tensile strain. In the active region, a strain buffer layer having an intermediate strain is formed between each quantum well layer and each of two barrier layers adjacent to the quantum well layer. Interfacial strain is thus reduced, improving high-output-power characteristics.

Abstract: An exposure system is provided with an exposure head formed of a red organic EL element which emits light in a red region and another organic EL element which emits light in a predetermined wavelength range shorter than the red region. The exposure system exposes a color photosensitive body containing therein at least a red silver-salt photosensitive material sensitive to the light in the red region and another silver-salt photosensitive material sensitive to the light in the predetermined wavelength range. An optical filter cuts the wavelength components which are shorter than the predetermined wavelength range and included in a sensitive range of the red silver-salt photosensitive material.

Abstract: A semiconductor laser has an active region which includes at least a quantum well layer and upper and lower optical waveguide layers and is of InxGa1?xAsyP1?y (0?x?1, 0?y?1). Upper and lower AlGaAs cladding layers are formed on opposite sides of the active region. At least one of the optical waveguide layers is not smaller than 0.25 ?m in thickness, and a part of the upper cladding layer on the upper optical waveguide layer is selectively removed up to the interface of the upper cladding layer and the upper optical waveguide layer.

Abstract: In a process for producing a substrate for use in a semiconductor element: a first GaN layer having a plurality of pits at its upper surface is formed; and then a second GaN layer is formed by growing a GaN crystal over the first GaN layer until the upper surface of the second GaN layer becomes flattened. Each of the above plurality of pits has an opening area of 0.005 to 100 &mgr;m2 and a depth of 0.1 to 10.0 &mgr;m.

Abstract: In a process for producing a substrate for use in a semiconductor element: a porous anodic alumina film having a great number of minute pores is formed on a surface of a base substrate; the surface of the base substrate is etched by using the porous anodic alumina film as a mask so as to form a great number of pits on the surface of the base substrate; the porous anodic alumina film is removed; and a GaN layer is formed on the surface of the base substrate by crystal growth.