A light-emitting diode chip is provided and includes: a first doping-type semiconductor layer, a second doping-type semiconductor layer, and a multiple quantum well structure layer formed between the first doping-type semiconductor layer and the second doping-type semiconductor layer. The multiple quantum well structure layer includes multiple first quantum well structures and at least one second quantum well structure stacked in a distance direction of the first and second doping-type semiconductor layers. The first quantum well structures are used to emit first color light, and the at least second well structure is used to emit second color light different from the first color light. A total number of well layer of the at least one second quantum well structure is 1/15 of a total number of well layer of the first quantum well structures located between the at least one second quantum well structure and the second doping-type semiconductor layer.

A nitride semiconductor light emitting device includes a substrate as a base and an n-type semiconductor layer grown on a surface side of the substrate. Antimony (Sb) is added to the n-type semiconductor layer so that a molar fraction is not less than 0.1% and is less than 1%. A concentration of an n-type impurity in the n-type semiconductor layer is lower than an electron concentration.

A nitride light emitting diode includes: an n-type nitride layer, a light emitting layer and a p-type nitride layer in sequence, wherein, the light emitting layer is a MQW structure composed of a barrier layer and a well layer, in which, an AlGaN electron tunneling layer is inserted into at least one well layer closing to the n-type nitride layer with barrier height greater than that of the barrier layer; in addition, the barriers of the AlGaN electron tunneling layer and the well layer are high enough so that electrons are difficult to transit towards thermionic emission direction, but mainly transit through tunneling in the InGaN well layers, which confines electron mobility and adjusts electron distribution. Hence, electrons have less chance to spill over into the P-type nitride layer.

There is provided a semiconductor multilayer structure, including: an n-type GaN layer; and a p-type GaN layer which is formed on the n-type GaN layer and into which Mg is ion-implanted, and generating an electroluminescence emission having a peak at a photon energy of 3.0 eV or more, by applying a voltage to a pn-junction formed by the n-type GaN layer and the p-type GaN layer.

A semiconductor light-emitting device including a P-type semiconductor cladding layer, an N-type semiconductor layer, a light-emitting layer, and a hole injection layer is provided. The P-type semiconductor cladding layer is doped with magnesium. The light-emitting layer is disposed between the P-type semiconductor cladding layer and the N-type semiconductor layer. The hole injection layer is disposed between the P-type semiconductor cladding layer and the light-emitting layer. The hole injection layer includes a first super lattice structure formed by alternately stacking a plurality of magnesium nitride layers and a plurality of semiconductor material layers. The chemical formula of each of the semiconductor material layers is Al.sub.xIn.sub.yGa.sub.1-x-yN, and 0x1, 0y1, and 0x+y1.

The present disclosure provides a light emitting element, wherein each of first and second semiconductor layers has first and second pits disposed therein, wherein the first pit has a first depth and the second pit has a second depth smaller than the first depth, and the first and second pits are coupled to each other, wherein a density of the second pits in an upper portion of the second semiconductor layer is lower than a density of the second pits in an upper portion of the first semiconductor layer, wherein a density of the first pits in the upper portion of the second semiconductor layer is equal to a density of the first pits in the upper portion of the first semiconductor layer.

A nitride-semiconductor light-emitting element includes an n-type nitride-semiconductor layer, a p-type nitride-semiconductor layer, and a light-emitting layer between the n-type nitride-semiconductor layer and the p-type nitride-semiconductor layer. The light-emitting layer has one or more quantum well layers and two or more barrier layers between which the quantum well layer(s) lie. A first barrier layer, which is the closest of the two or more barrier layers to the p-type nitride-semiconductor layer, has a thickness equal to or smaller than that of the barrier layer(s) different from the first. There is an undoped layer, a layer of a nitride semiconductor represented by a general formula Al.sub.sGa.sub.tIn.sub.uN (0<s<1, 0<t<1, 0u<1, and s+t+u=1), between the first barrier layer and the p-type nitride-semiconductor layer.

A III-nitride light emitting layer is disposed between an n-type region and a p-type region in a double heterostructure. At least a portion of the III-nitride light emitting layer has a graded composition.

An ultraviolet light emitting apparatus may include a chamber, at least one semiconductor light emitting device, an electron beam irradiation source, and first and second connection electrodes configured to apply a voltage from an external power source to the at least one semiconductor light emitting device. The chamber may define an internal space and include a light emission window. The at least one semiconductor light emitting device may be on the light emission window and include a first conductivity type nitride semiconductor layer, an undoped nitride semiconductor layer, and an active layer between the first conductivity type nitride semiconductor layer and the undoped nitride semiconductor layer. The electron beam irradiation source may be in the internal space of the chamber and configured to irradiate an electron beam onto the undoped nitride semiconductor layer.

A nitride semiconductor structure and a semiconductor light emitting device including the same are revealed. The nitride semiconductor structure includes a multiple quantum well structure formed by a plurality of well layers and barrier layers stacked alternately. One well layer is disposed between every two barrier layers. The barrier layer is made of Al.sub.xIn.sub.yGa.sub.1-x-yN (0<x<1, 0<y<1, 0<x+y<1) while the well layer is made of In.sub.zGa.sub.1-zN (0<z<1). Thereby quaternary composition is adjusted for lattice match between the barrier layers and the well layers. Thus crystal defect caused by lattice mismatch is improved.