A semiconductor light emitting element includes: a first light emitting part comprising: a first n-side nitride semiconductor layer; a first active layer located on the first n-side nitride semiconductor layer; and a first p-side nitride semiconductor layer located on the first active layer; and a second n-side nitride semiconductor layer. A bonding face of the first light emitting part and a bonding face of the second n-side nitride semiconductor layer are directly bonded. At least one void is present between the bonding face of the first light emitting part and the bonding face of the second n-side nitride semiconductor layer.

A semiconductor light-emitting device includes an n-type semiconductor layer, a light-emitting structure, a first electron blocking layer, a second electron blocking layer, and a p-type hole injection layer, which are sequentially stacked in such order. The light-emitting structure includes well layers and barrier layers which are stacked alternately. The first electron blocking layer contacts a last one of the barrier layers of the light-emitting structure and has an energy band gap (E.sub.g3) that is larger than an energy band gap (E.sub.g4) of the second electron blocking layer. The energy band gap (E.sub.g4) of the second electron blocking layer is larger than an energy band gap (E.sub.g2) of the barrier layers, and an energy band gap (E.sub.g5) of the p-type hole injection layer is smaller than the energy band gap (E.sub.g2) of the barrier layers.

A micro light-emitting diode device includes a substrate, a micro light-emitting diode, and a cathode transparent electrode. The micro light-emitting diode is disposed on the substrate and includes a p-type III-nitride layer, a first n-type III-nitride layer above the p-type III-nitride layer, a second n-type III-nitride layer above the first n-type III-nitride layer, and an active layer between the p-type and first n-type III-nitride layers. The second n-type III-nitride layer contains aluminum and has top and bottom surfaces. A refractive index of the second n-type III-nitride layer is smaller than a refractive index of the first n-type III-nitride layer and varies in a monotonically non-decreasing manner from the top surface. The refractive index of the second n-type III-nitride layer is larger at the bottom surface than at the top surface. The cathode transparent electrode is in contact with the top surface.

A light-emitting diode epitaxial structure and a method for forming the same are provided. The light-emitting diode epitaxial structure includes: an N-type semiconductor structure, a quantum well light-emitting layer and a P-type semiconductor structure which are stacked. The quantum well light-emitting layer is disposed between the N-type semiconductor structure and the P-type semiconductor structure. The P-type semiconductor structure includes a P-type current spreading layer and a P-type confinement layer, and the P-type confinement layer is disposed between the quantum well light-emitting layer and the P-type current spreading layer. A material of the P-type current spreading layer has a first lattice constant, a material of the P-type confinement layer has a second lattice constant, and a mismatch between the first lattice constant and the second lattice constant is less than or equal to 1%.

A semiconductor device, includes: a first conductive type semiconductor region including a first semiconductor structure, wherein the first semiconductor structure includes one or more pairs of stack, the one or more pairs of stack respectively includes a first layer and a second layer, the first layer includes Al.sub.xGa.sub.1-xN, the second layer includes Al.sub.yGa.sub.1-yN, wherein 0x<1, 0<y<1, x<y, wherein one of the one or more pairs of stack includes an interface region located between the first layer and the second layer adjacent to the first layer; a second conductive type semiconductor region located on the first conductive type semiconductor region; and an active region located between the first conductive type semiconductor region and the second conductive type semiconductor region; wherein the first semiconductor structure includes a first dopant having a first doping concentration with a peak value at the interface region.

To improve the luminous efficiency of a UV light-emitting device, the UV light-emitting devices disclosed herein have an AlGaN-based crystal or an InAlGaN-based crystal, and comprise an emission layer, at least one electron blocking layer, a first p-type doped layer, and a composition gradient layer in which the Al composition ratio varies depending on the position over a thickness direction of the layer stack, stacked in this order in the direction of the flow of electrons. The Al composition ratio varies depending on the position over the thickness direction in the composition gradient layer. The UV light-emitting devices are implemented as UV-region light-emitting diodes and laser diodes.

A method for etching a semiconductor structure is provided, the semiconductor structure includes a sub-surface quantum structure of a first III-V semiconductor material, beneath a surface layer of a second III-V semiconductor material having a charge carrier density of less than 510.sup.17 cm.sup.3. The sub-surface quantum structure may include, for example, a quantum well, or a quantum wire, or a quantum dot. The method includes the steps of exposing the surface layer to an electrolyte, and applying a potential difference between the first III-V semiconductor material and the electrolyte, to electrochemically etch the sub-surface quantum structure to form a plurality of nanostructures, while the surface layer is not etched. A semiconductor structure, uses thereof, and devices incorporating such semiconductor structures are further provided.

Provided is an n-type GaN crystal, which has two main surfaces facing opposite directions from each other. One of the two main surfaces has a Ga polarity and is inclined at an angle of 0 to 10 with respect to the (0001) crystal plane. The n-type GaN crystal yields at least one X-ray anomalous transmission image having a square area of 10 mm10 mm, preferably 15 mm15 mm, and more preferably 20 mm20 mm. In addition, the n-type GaN crystal has a Si concentration of 510.sup.16 atoms/cm.sup.3 or higher, O concentration of 310.sup.16 atoms/cm.sup.3 or lower, and/or a H concentration of 110.sup.17 atoms/cm.sup.3 or lower.

Exemplary processing methods of forming a semiconductor structure may include forming subpixels on a substrate. Each of the subpixels may include a gallium-and-nitrogen-containing layer formed on an exposed portion of a nucleation layer on the substrate. The subpixels may further include a porosified region formed on or in the gallium-and-nitrogen-containing region, and an active region formed on the porosified region. The active region may include an indium-gallium-and-nitrogen-containing material. The processing methods may further include forming a first reflection layer around one of the subpixels, wherein the first reflection layer includes a first metal layer. The methods may additionally include forming a second reflection layer around another of the subpixels, wherein the second reflection layer includes a second metal that is different than the first metal.

A light emitting diode includes a first type semiconductor pattern disposed over a substrate, an active pattern disposed over the first type semiconductor pattern, a second type semiconductor pattern disposed over the active pattern, an ion implantation region and a plurality of electrodes. A polarity of the first type semiconductor pattern is opposite to a polarity of the second type of the second type semiconductor pattern. The ion implantation region at least surrounds and encapsulates a side wall of the second type semiconductor pattern. The electrodes are disposed over the first type semiconductor pattern and the second type semiconductor pattern respectively and separated from one another.