Disclosed is in the embodiment is a semiconductor device comprising: a first conductive semiconductor layer; a second conductive semiconductor layer; an active layer disposed between the second conductive semiconductor layer and the second conductive semiconductor layer; a first electrode electrically connected to the first conductive semiconductor layer; and a second electrode electrically connected to the second conductive semiconductor layer, wherein the first conductive semiconductor layer includes a first sub semiconductor layer, a third sub semiconductor layer and a second sub semiconductor layer disposed between the first sub semiconductor layer and the third sub semiconductor layer, wherein proportion of aluminum in the first sub semiconductor layer and the third sub semiconductor layer is larger than an proportion of aluminum in the active layer, and an proportion of aluminum in the second sub semiconductor layer is smaller than the proportion of aluminum in the first sub semiconductor layer and the third sub semiconductor layer, wherein the second conductive semiconductor layer includes a current injection layer of which proportion of aluminum decreases as a distance from the active layer increases, the first electrode is disposed on the second sub semiconductor layer, the second electrode is disposed on the current injection layer, and the ratio of the average value of the proportion of aluminum in the second sub semiconductor layer to the average value of the proportion of aluminum in the current injection layer is 1:0.12 to 1:1.6.

Disclosed is in the embodiment is a semiconductor device comprising: a first conductive semiconductor layer; a second conductive semiconductor layer; an active layer disposed between the second conductive semiconductor layer and the second conductive semiconductor layer; a first electrode electrically connected to the first conductive semiconductor layer; and a second electrode electrically connected to the second conductive semiconductor layer, wherein the first conductive semiconductor layer includes a first sub semiconductor layer, a third sub semiconductor layer and a second sub semiconductor layer disposed between the first sub semiconductor layer and the third sub semiconductor layer, wherein proportion of aluminum in the first sub semiconductor layer and the third sub semiconductor layer is larger than an proportion of aluminum in the active layer, and an proportion of aluminum in the second sub semiconductor layer is smaller than the proportion of aluminum in the first sub semiconductor layer and the third sub semiconductor layer, wherein the second conductive semiconductor layer includes a current injection layer of which proportion of aluminum decreases as a distance from the active layer increases, the first electrode is disposed on the second sub semiconductor layer, the second electrode is disposed on the current injection layer, and the ratio of the average value of the proportion of aluminum in the second sub semiconductor layer to the average value of the proportion of aluminum in the current injection layer is 1:0.12 to 1:1.6.

A pattern structure for a display device includes a substrate, a protrusion pattern on the substrate, a first conductive pattern covering an upper surface of the protrusion pattern, an interlayer insulating layer on the first conductive pattern and including a contact hole, and a second conductive pattern on the interlayer insulating layer and connected to the first conductive pattern. The contact hole overlaps the protrusion pattern and the first conductive pattern.

A pattern structure for a display device includes a substrate, a protrusion pattern on the substrate, a first conductive pattern covering an upper surface of the protrusion pattern, an interlayer insulating layer on the first conductive pattern and including a contact hole, and a second conductive pattern on the interlayer insulating layer and connected to the first conductive pattern. The contact hole overlaps the protrusion pattern and the first conductive pattern.

A light-emitting device can include a conductive support structure comprising a metal; a GaN-based semiconductor structure disposed on the conductive support structure, the GaN-based semiconductor structure including a p-type GaN-based layer, a GaN-based active layer and an n-type GaN-based layer, in which the GaN-based semiconductor structure has a first surface, a side surface and a second surface, in which the first surface, relative to the second surface, is proximate to the conductive support structure, in which the second surface is opposite to the first surface, in which the conductive support structure is thicker than the p-type GaN-based semiconductor layer, and the conductive support structure is thicker than the n-type GaN-based semiconductor layer; a p-type electrode disposed on the conductive support structure; an n-type electrode disposed on the second surface of the GaN-based semiconductor structure; and a passivation layer disposed on the side surface and the second surface of the GaN-based semiconductor structure.

A light-emitting device can include a conductive support structure comprising a metal; a GaN-based semiconductor structure disposed on the conductive support structure, the GaN-based semiconductor structure including a p-type GaN-based layer, a GaN-based active layer and an n-type GaN-based layer, in which the GaN-based semiconductor structure has a first surface, a side surface and a second surface, in which the first surface, relative to the second surface, is proximate to the conductive support structure, in which the second surface is opposite to the first surface, in which the conductive support structure is thicker than the p-type GaN-based semiconductor layer, and the conductive support structure is thicker than the n-type GaN-based semiconductor layer; a p-type electrode disposed on the conductive support structure; an n-type electrode disposed on the second surface of the GaN-based semiconductor structure; and a passivation layer disposed on the side surface and the second surface of the GaN-based semiconductor structure.

A group III nitride semiconductor light-emitting element comprises, in the following order: an n-type group III nitride semiconductor layer; a group III nitride semiconductor laminated body obtained by alternately laminating a barrier layer and a well layer narrower in bandgap than the barrier layer in the stated order so that the number of barrier layers and the number of well layers are both N, where N is an integer; an AlN guide layer; and a p-type group III nitride semiconductor layer. The AlN guide layer has a thickness of 0.7 nm or more and 1.7 nm or less. An Nth well layer in the group III nitride semiconductor laminated body and the AlN guide layer are in contact with each other, or a final barrier layer is further provided between the Nth well layer and the AlN guide layer.

A group III nitride semiconductor light-emitting element comprises, in the following order: an n-type group III nitride semiconductor layer; a group III nitride semiconductor laminated body obtained by alternately laminating a barrier layer and a well layer narrower in bandgap than the barrier layer in the stated order so that the number of barrier layers and the number of well layers are both N, where N is an integer; an AlN guide layer; and a p-type group III nitride semiconductor layer. The AlN guide layer has a thickness of 0.7 nm or more and 1.7 nm or less. An Nth well layer in the group III nitride semiconductor laminated body and the AlN guide layer are in contact with each other, or a final barrier layer is further provided between the Nth well layer and the AlN guide layer.

Methods and a device for cascading broadband emission are described. An example device can comprise a substrate, a bottom contact layer above at least a portion of the substrate, and a plurality of emission regions above the bottom contact layer. The plurality of emission regions can be disposed one above another. Each of the plurality of emission regions can be configured with different respective band gaps to emit radiation of different wavelengths. The device can comprise a plurality of tunnel junctions. Each of the tunnel junctions can be disposed between at least two corresponding emission regions of the plurality of emission regions. The device can comprise a top contact layer above the plurality of emission regions.

Methods and a device for cascading broadband emission are described. An example device can comprise a substrate, a bottom contact layer above at least a portion of the substrate, and a plurality of emission regions above the bottom contact layer. The plurality of emission regions can be disposed one above another. Each of the plurality of emission regions can be configured with different respective band gaps to emit radiation of different wavelengths. The device can comprise a plurality of tunnel junctions. Each of the tunnel junctions can be disposed between at least two corresponding emission regions of the plurality of emission regions. The device can comprise a top contact layer above the plurality of emission regions.