A refractive index of the active layer is obtained by a photoluminescence inspection and an equivalent refractive index of the optical semiconductor element is computed. A refractive index of the optical waveguide layer is obtained by a photoluminescence inspection and an equivalent refractive index of the optical waveguide is computed. A film thickness of the refractive index adjustment layer is adjusted by etching the refractive index adjustment layer so that the equivalent refractive index of the optical semiconductor element and the equivalent refractive index of the optical waveguide are matched to each other. After adjusting the film thickness of the refractive index adjustment layer, a contact layer is formed on the second cladding layer and the refractive index adjustment layer. The optical waveguide is a passive waveguide to which no electrical field is applied and no current is injected.

Disclosed is an ultraviolet light-emitting device. The light-emitting device includes: an n-type contact layer including a GaN layer; a p-type contact layer including an AlGaN or AlInGaN layer; and an active region of multiple quantum well structure positioned between the n-type contact layer and the p-type contact layer. In addition, the active region of multiple quantum well structure includes a GaN or InGaN layer with a thickness less than 2 nm, radiating an ultraviolet ray with a peak wavelength of 340 nm to 360 nm.

The present invention provides a light emitting device which emit light having a high-order level without increasing a current injection density to an active layer. A light emitting device according to the present invention includes an upper electrode layer, a lower electrode layer, and an active layer provided between them. In this case, light is emitted by injection of electric current to the active layer through the upper electrode layer and the lower electrode layer, the active layer has a plurality of quantum-confined structures, and a first quantum-confined structure has a ground level having an energy level E.sub.0 and a high-order level having an energy level E.sub.1, and a second quantum-confined structure has an energy level E.sub.2 which is higher than the E.sub.0, and the E.sub.1 and the E.sub.2 are substantially matched.

Disclosed is a semiconductor light emitting device including: multiple semiconductor layers including a first semiconductor layer, a second semiconductor layer, and an active layer; an electrode electrically connected with the multiple semiconductor layers; a light absorption barrier disposed about at least the electrode; and a non-conductive reflective film adapted to cover the multiple semiconductor layers, the light absorption barrier and the electrode and to reflect light from the active layer, wherein the non-conductive reflective film has an abnormal region of a lower reflectivity around the electrode due to a height difference between the light absorption barrier and the electrode, wherein a portion of the non-conductive reflective film exposed from the electrode is made longer than the abnormal region as seen in a cross-sectional view of the electrode.

A light-emitting element according to an embodiment of the present document has a transparent electrode having an opening, and the transparent electrode has a protrusion on a side surface of the opening. A second electrode pad is arranged on the opening of the transparent electrode, and abuts the protrusion. Accordingly, peeling of the second electrode pad can be prevented, thereby improving the reliability of the light-emitting element.

A semiconductor light emitting device includes a first conductivity-type semiconductor layer; an active layer disposed on the first conductivity-type semiconductor layer, and including: a plurality of quantum barrier layers; and a plurality of quantum well layers containing indium (In), the plurality of quantum barrier layers and the plurality of quantum well layers being alternately stacked on each other, the plurality of quantum well layers comprising a first quantum well layer and a second quantum well layer; and a second conductivity-type semiconductor layer disposed on the active layer, wherein the first quantum well layer is disposed closer to the first conductivity-type semiconductor layer than the second quantum well layer, wherein the second quantum well layer is disposed closer to the second conductivity-type semiconductor layer than the first quantum well layer, wherein a thickness of the second quantum well layer is greater than a thickness of the first quantum well layer, and wherein each of the first and the second quantum well layers comprises at least one graded layer having a varying amount of In composition, and the at least one graded layer of the second quantum well layer has a greater thickness than the at least one graded layer of the first quantum well layer.

A light emitting structure includes lower and upper semiconductor layers having different conductive types, and an active layer disposed between the lower and upper semiconductor layers. The light emitting structure is provided on the substrate. A first electrode layer provided on the upper semiconductor layer includes a first adhesive layer and a first bonding layer overlapping each other. A reflective layer is not provided between the first adhesive layer and the first bonding layer.

A semiconducting structure configured to emit electromagnetic radiation. The structure includes a first zone and a second zone with first and second types of conductivities respectively opposite to each other, the first and second zones being connected to each other to form a semiconducting junction. The first zone includes at least a first and a second part, the first and the second parts being separated from each other by an intermediate layer, as a spreading layer, extending approximately parallel to a junction plane along a major part of the junction. The spreading layer can cause spreading of carriers in the plane of the spreading 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.

Diode includes light emitting region, first metal layer, dielectric layer, and second metal layer. Light emitting diode includes n-type group III-nitride portion, p-type group III-nitride layer, and light emitting region sandwiched between n- and p-type layers. First metal layer may be coupled to p-type III-N portion and plurality of first terminals. First metal layer and p-type III-N portion may have substantially similar lateral size that is smaller than 200 micrometers. A portion of light emitting region and first metal layer may include a single via. Electrically-insulating layer may be coupled to first metal layer and sides of the single via. First terminals may be exposed from electrically-insulating layer. Second metal layer may include second terminal and may be coupled to electrically-insulating layer and to n-type III-N portion through the single via. The thickness of the diode excluding second terminal may be between 2 and 20 micrometers. Other embodiments are described.