Abstract: A GaN-containing semiconductor light emitting device includes: an n-type semiconductor layer formed of GaN-containing semiconductor, an active layer formed on the n-type semiconductor layer, formed of GaN-containing semiconductor, and having a multiple quantum well structure including a plurality of barrier layers and well layers stacked alternately, and a p-type semiconductor layer formed on the active layer and formed of GaN-containing semiconductor, wherein: the barrier layers comprise: a first barrier layer disposed nearest to the n-type semiconductor layer among the barrier layers and formed of a GaN/AlGaN layer, and second barrier layers disposed nearer to the p-type semiconductor layer than the first barrier layer and including an InGaN/GaN layer which has a layered structure of a InGaN sublayer and a GaN sublayer; and the well layers are each formed of an InGaN layer having a narrower band gap than that in the InGaN sublayer.

Abstract: A semiconductor light-emitting element includes a first semiconductor layer having a first conduction type, a second semiconductor layer having a second conduction type, an active layer provided between the first and second semiconductor layers, a polarity inversion layer provided on the second semiconductor layer, and a third semiconductor layer having the second conduction type provided on the polarity inversion layer. Crystal orientations of the first through third semiconductor layers are inverted, with the polarity inversion layer serving as a boundary. The first and third semiconductor layers have uppermost surfaces made from polar faces having common constitutional elements. Hexagonal conical protrusions arising from a crystal structure are formed at outermost surfaces of the first and third semiconductor layers. The first through third semiconductor layers are made from a wurtzite-structure group III nitride semiconductor, and are layered along a C-axis direction of the crystal structure.

Abstract: In an optical semiconductor device including a first semiconductor layer of a first conductivity type, an active layer provided on the first semiconductor layer, a second semiconductor layer of a second conductivity type provided on the active layer, an insulating layer provided on a part of the second semiconductor layer, an uneven semiconductor layer of the second conductivity type provided on another part of the second semiconductor layer, and an electrode layer provided on the insulating layer and the uneven semiconductor layer, a density of carriers of the second conductivity type being larger at a tip portion of the uneven semiconductor layer than at a bottom portion of the uneven semiconductor layer.

Abstract: A nitride semiconductor light emitting device includes: a substrate for growing nitride semiconductor of a hexagonal crystal structure; a first nitride semiconductor layer of a first conductivity type formed above the substrate; an active layer formed on the first nitride semiconductor layer for emitting light when current flows; a second nitride semiconductor layer of a second conductivity type opposite to the first conductivity type formed on the active layer; texture formed above at least a partial area of the second nitride semiconductor layer and having a plurality of protrusions of a pyramid shape, each of the protrusions including a lower layer made of nitride semiconductor doped with impurities of the second conductivity type and an upper layer made of nitride semiconductor not intentionally doped with impurities; and a transparent electrode covering surfaces of the second nitride semiconductor layer and the texture.

Abstract: In an optical semiconductor device including a first semiconductor layer of a first conductivity type, an active layer provided on the first semiconductor layer, a second semiconductor layer of a second conductivity type provided on the active layer, an insulating layer provided on a part of the second semiconductor layer, an uneven semiconductor layer of the second conductivity type provided on another part of the second semiconductor layer, and an electrode layer provided on the insulating layer and the uneven semiconductor layer, a density of carriers of the second conductivity type being larger at a tip portion of the uneven semiconductor layer than at a bottom portion of the uneven semiconductor layer.

Abstract: In an exemplary embodiment of the invention, a semiconductor light-emitting element includes a first semiconductor layer having a first conduction type, a second semiconductor layer having a second conduction type, an active layer provided between the first and second semiconductor layers. The semiconductor light-emitting element also includes a polarity inversion layer provided on the second semiconductor layer, and a third semiconductor layer provided on the polarity inversion layer. The third semiconductor layer has the second conduction type. The crystal orientations of the first through third semiconductor layers are inverted, with the polarity inversion layer serving as a boundary. The first and third semiconductor layers have uppermost surfaces that are made from polar faces having common constitutional elements. Hexagonal conical protrusions arising from a crystal structure are formed at the outermost surfaces of the first and third semiconductor layers.

Abstract: A nitride semiconductor light emitting device includes: a substrate for growing nitride semiconductor of a hexagonal crystal structure; a first nitride semiconductor layer of a first conductivity type formed above the substrate; an active layer formed on the first nitride semiconductor layer for emitting light when current flows; a second nitride semiconductor layer of a second conductivity type opposite to the first conductivity type formed on the active layer; texture formed above at least a partial area of the second nitride semiconductor layer and having a plurality of protrusions of a pyramid shape, each of the protrusions including a lower layer made of nitride semiconductor doped with impurities of the second conductivity type and an upper layer made of nitride semiconductor not intentionally doped with impurities; and a transparent electrode covering surfaces of the second nitride semiconductor layer and the texture.