Abstract:
A semiconductor device includes a p-type nitride semiconductor layer (14); and a p-side electrode (18) including a palladium oxide film (30) connected to a surface of the nitride semiconductor layer (14).
Abstract:
A semiconductor light emitting element includes a first clad layer of a first conductivity type provided on a substrate; an active layer provided on the first clad layer; a second clad layer of a second conductivity type provided on the active layer, an upper portion of the second clad layer implements a ridge extending in a predetermined direction; a pair of first current block layers provided on the second clad layer sandwiching the ridge along the extending direction; and a pair of second current block layers provided between the first current block layers on the second clad layer and at sidewalls of the ridge to be contacted with the first current block layers, sandwiching selectively a region including an edge of the ridge, the second current block layers having a refractive index larger than the first current block layers at an emission peak wavelength of the active layer.
Abstract:
A light-emitting device is provided, which includes a package having a first portion and a second portion surrounding it, a semiconductor light-emitting element mounted on the first portion and emitting a light having an emission peak in a near-ultraviolet region, a transparent resin layer covering the semiconductor light-emitting element and contacted with the package, and a laminated body formed on the transparent resin layer with end faces of the laminated body being contacted with the second portion. The transparent resin layer has an arch-like outer profile perpendicular cross section. The laminated body has an arch-like outer profile in perpendicular cross section and comprises a red fluorescent layer, a yellow fluorescent layer, a green fluorescent layer and a blue fluorescent layer laminated in the mentioned order. The yellow fluorescent layer has a top portion which is made larger in thickness than that of the end face portions thereof.
Abstract:
A light-emitting device includes a support substrate which includes a light-emitting layer and a light extraction surface, and a light transmission layer, formed on the light extraction surface of the support substrate, having a periodic refractive index distribution structure in an in-plane direction and a thickness direction, the light transmission layer including a plurality of projections formed of a having a refractive index lower than that of the support substrate.
Abstract:
A semiconductor device has an active layer, a first semiconductor layer of first conductive type, an overflow prevention layer disposed between the active layer and the first semiconductor layer, which is doped with impurities of first conductive type and which prevents overflow of electrons or holes, a second semiconductor layer of first conductive type disposed at least one of between the active layer and the overflow prevention layer and between the overflow prevention layer and the first semiconductor layer, and an impurity diffusion prevention layer disposed between the first semiconductor layer and the active layer, which has a band gap smaller than those of the overflow prevention layer, the first semiconductor layer and the second semiconductor layer and which prevents diffusion of impurities of first conductive type.
Abstract:
A light-emitting device is provided, which includes a substrate having a plane surface, a semiconductor light-emitting element mounted on the plane surface of the substrate and which emits light in a range from ultraviolet ray to visible light, a first light transmissible layer formed above the substrate and covering the semiconductor light-emitting element, a phosphor layer formed above the first light transmissible layer and containing phosphor particles and matrix, and a second light transmissible layer formed above the phosphor layer and contacting with the plane surface of the substrate. The surface of the phosphor layer has projections reflecting shapes of the phosphor particles.
Abstract:
A semiconductor device has an active layer, a first semiconductor layer of first conductive type, an overflow prevention layer disposed between the active layer and the first semiconductor layer, which is doped with impurities of first conductive type and which prevents overflow of electrons or holes, a second semiconductor layer of first conductive type disposed at least one of between the active layer and the overflow prevention layer and between the overflow prevention layer and the first semiconductor layer, and an impurity diffusion prevention layer disposed between the first semiconductor layer and the active layer, which has a band gap smaller than those of the overflow prevention layer, the first semiconductor layer and the second semiconductor layer and which prevents diffusion of impurities of first conductive type.
Abstract:
A semiconductor laser is formed of gallium nitride series compound semiconductor and has a double hetero structure including an MQW (multiple quantum well) active layer held between p-type and n-type AlGaN clad layers. The double hetero structure is held between p-type and n-type contact layers. An InGaN optical absorption layer having an optical absorption coefficient larger than the clad layer which has the same conductivity type as the contact layer and is formed adjacent to the contact layer is formed in at least one of the contact layers and an InAlGaN optical guided mode control layer (layer of small refractive index) having an refractive index smaller than the clad layer is formed on the exterior of the optical absorption layer.
Abstract:
In order to remove the problems in conventional nitride compound semiconductor laser structures, namely, high operation voltage caused by a high resistance in a p-type layer and a high contact resistance of an electrode, damage to the crystal caused by dry etching, insufficient current injection, and the need for a high current density, a nitride compound semiconductor light emitting device has current blocking layers made of n-type B(1−x−y−z)InxAlyGazN (0≦x≦1, 0≦y≦1, 0≦z≦1) single crystal containing an oxide of a predetermined metal, carbon and impurities exhibiting p-type and n-type conductivity, or i-type B(1−x−y−z)InxAlyGazN (0≦x≦1, 0≦y≦1, 0≦z≦1) single crystal in which carriers are inactivated by hydrogen or oxygen to realize an internal current blocking structure without the need for dry etching. By applying a reverse bias voltage, the semiconductor can be activated only along a current path, and the remainder region is utilized as a current blocking layer. When the n-side electrode has a unique three-layered structure, a reduction in contact resistance and good wire bonding are promised.
Abstract translation:为了消除常规氮化物化合物半导体激光器结构中的问题,即由p型层中的高电阻引起的高操作电压和电极的高接触电阻,由干蚀刻引起的晶体损坏,电流不足 注入,并且需要高电流密度,氮化物化合物半导体发光器件具有由n型B(1-xyz)In x AlyGazN(0≤x≤1,0<= y <= 1)形成的电流阻挡层 ,0 <= z <= 1)含有预定金属的氧化物的单晶,碳和表现出p型和n型导电性的杂质,或i型B(1-xyz)In x AlyGazN(0 <= x < 1,0 <= y <= 1,0 <= z <= 1)其中载体被氢或氧灭活以实现内部电流阻挡结构而不需要干法蚀刻的单晶。 通过施加反向偏置电压,半导体只能沿着电流路径被激活,并且剩余区域被用作电流阻挡层。 当n侧电极具有独特的三层结构时,承诺了接触电阻的降低和良好的引线接合。
Abstract:
A gallium nitride-based compound semiconductor laser has a double-heterojunction structure, in which an active layer is sandwiched between cladding layers, on a sapphire substrate. A GaN current blocking layer having a striped opening portion is formed on the p-cladding layer. A p-GaN buried layer and a contact layer through which a current is injected into the opening portion of the current blocking layer and which are larger in area than the opening portion are formed. The active layer has a multiple quantum well structure constituted by a cyclic structure formed by cyclically stacking two types of InGaAlN layers which have different band gaps and are 10 nm or more thick.