A semiconductor layer structure may include a substrate, a blocking layer disposed over the substrate, and one or more epitaxial layers disposed over the blocking layer. The blocking layer may have a thickness of between 50 nanometers (nm) and 4000 nm. The blocking layer may be configured to suppress defects from the substrate propagating to the one or more epitaxial layers. The one or more epitaxial layers may include a quantum-well layer that includes a quantum-well intermixing region formed using a high temperature treatment.

A semiconductor device comprising a nominally or exactly or equivalent orientation silicon substrate on which is grown directly a <100 nm thick nucleation layer (NL) of a III-V compound semiconductor, other than GaP, followed by a buffer layer of the same compound, formed directly on the NL, optionally followed by further III-V semiconductor layers, followed by at least one layer containing III-V compound semiconductor quantum dots, optionally followed by further III-V semiconductor layers. The NL reduces the formation and propagation of defects from the interface with the silicon, and the resilience of quantum dot structures to dislocations enables lasers and other semiconductor devices of improved performance to be realized by direct epitaxy on nominally or exactly or equivalent orientation silicon.

In some embodiments, a semiconductor structure includes: a first region comprising a first epitaxial oxide material; a second region comprising a second epitaxial oxide material; and a chirp layer located between the first and the second regions. The chirp layer can include alternating layers of a plurality of wide bandgap epitaxial oxide material layers (WBG layers) and a plurality of narrow bandgap epitaxial oxide material layers (NBG layers), wherein thicknesses of the NBG layers and the WBG layers change throughout the chirp layer. The WBG layer can comprise (Al.sub.x1Ga.sub.1−x1).sub.y1O.sub.z1, wherein x1 is from 0 to 1, wherein y1 is from 1 to 3, and wherein z1 is from 2 to 4. The NBG layer can comprise (Al.sub.x2Ga.sub.1x−2).sub.y2O.sub.z2, wherein x2 is from 0 to 1, wherein y2 is from 1 to 3, and wherein z2 is from 2 to 4, and wherein x1 and x2 are different from one another.

In some embodiments, a semiconductor structure includes: a first epitaxial oxide semiconductor layer; a metal layer; and a contact layer adjacent to the metal layer, and between the first epitaxial oxide semiconductor layer and the metal layer. The contact layer can include an epitaxial oxide semiconductor material. The contact layer can also include a region comprising a gradient in a composition of the epitaxial oxide semiconductor material adjacent to the metal layer, or a gradient in a strain of the epitaxial oxide semiconductor material over a region adjacent to the metal layer.

A light emitting apparatus includes a laminated structure including a plurality of columnar section assemblies each formed of p columnar sections. The p columnar sections each include a light emitting layer. When viewed in the lamination direction of the laminated structure, the ratio of the maximum width to the minimum width of the light emitting layer in each of q first columnar sections out of the p columnar sections is greater than the ratio of the light emitting layer in each of r second columnar sections out of the p columnar sections. The light emitting layer in each of the p columnar sections does not have a rotationally symmetrical shape. The parameter p is an integer greater than or equal to 2. The parameter q is an integer greater than or equal to 1 but smaller than p. The parameter r is an integer that satisfies r=p−q.

A semiconductor light emitting device includes a mount section having an insulating property connected to a heat sink, a plurality of semiconductor laser elements disposed on the mount section, and a heat radiation block having an insulating property disposed on the plurality of semiconductor laser elements. A first wiring made of a metal is disposed on an upper surface of the mount section, and a second wiring made of a metal is disposed on a lower surface of the heat radiation block, a part of the second wiring being electrically connected to the first wiring. By electrically connecting the first wiring and the second wiring to each of the plurality of semiconductor laser elements, the plurality of semiconductor laser elements are connected in series, and have a same polarity with each other at a side that each of the plurality of semiconductor laser elements is connected to the first wiring.

A semiconductor light emitting device includes a mount section having an insulating property connected to a heat sink, a plurality of semiconductor laser elements disposed on the mount section, and a heat radiation block having an insulating property disposed on the plurality of semiconductor laser elements. A first wiring made of a metal is disposed on an upper surface of the mount section, and a second wiring made of a metal is disposed on a lower surface of the heat radiation block, a part of the second wiring being electrically connected to the first wiring. By electrically connecting the first wiring and the second wiring to each of the plurality of semiconductor laser elements, the plurality of semiconductor laser elements are connected in series, and have a same polarity with each other at a side that each of the plurality of semiconductor laser elements is connected to the first wiring.

In an embodiment a semiconductor layer sequence includes a pre-barrier layer including AlGaN, a pre-quantum well including InGaN having a first band gap, a multi-quantum well structure including a plurality of alternating main quantum wells of InGaN having a second band gap and main barrier layers of AlGaN or AlInGaN, wherein the second band gap is smaller than the first band gap and the main quantum wells are configured to generate a radiation having a wavelength of maximum intensity between 365 nm and 490 nm inclusive, a post-quantum well with a third band gap which is larger than the second band gap, a post-barrier layer including AlGaN or AlInGaN and an electron-blocking layer including AlGaN.

A semiconductor light emitting device includes a mount section having an insulating property connected to a heat sink, a plurality of semiconductor laser elements disposed on the mount section, and a heat radiation block having an insulating property disposed on the plurality of semiconductor laser elements. A first wiring made of a metal is disposed on an upper surface of the mount section, and a second wiring made of a metal is disposed on a lower surface of the heat radiation block, a part of the second wiring being electrically connected to the first wiring. By electrically connecting the first wiring and the second wiring to each of the plurality of semiconductor laser elements, the plurality of semiconductor laser elements are connected in series, and have a same polarity with each other at a side that each of the plurality of semiconductor laser elements is connected to the first wiring.

To increase the maximum operating temperature of quantum cascade lasers of a terahertz region, a quantum cascade laser element 1000 according to the present invention has a semiconductor superlattice structure sandwiched between a pair of electrodes, the semiconductor superlattice structure has an active region 100 that emits electromagnetic waves of a frequency in a THz region under an external voltage applied through the pair of electrodes for operation, and the active region 100 has plural unit structures 10U, each of which is repeatedly layered over one another. Each of the unit structures 10U has a double quantum well structure formed of a first well layer 10W1 and a second well layer 10W2 separated from each other by a barrier layer, the first well layer 10W1 and the second well layer 10W2 have compositions different from each other, and when the external voltage is not being applied, potential energy for electrons in the second well layer 10W2 is lower than that in the first well layer 10W1.