An optoelectronic component includes a layer structure which has a first gallium nitride layer and an aluminum-containing nitride intermediate layer. In this case, the aluminum-containing nitride intermediate layer adjoins the first gallium nitride layer. The layer structure has an undoped second gallium nitride layer which adjoins the aluminum-containing nitride intermediate layer.

In various embodiments, light-emitting devices incorporate graded layers with compositional offsets at one or both end points of the graded layer to promote formation of two-dimensional carrier gases and polarization doping, thereby enhancing device performance.

A method of forming an integrated circuit employs a plurality of layers formed on a substrate including i) n-type modulation doped quantum well structure (MDQWS) structure with n-type charge sheet, ii) p-type MDQWS, iii) undoped spacer layer formed on the n-type charge sheet, iv) p-type layer(s) formed on the undoped spacer layer, v) p-type etch stop layer formed on the p-type layer(s) of iv), and vi) p-type layers (including p-type ohmic contact layer(s)) formed on the p-type etch stop layer. An etch operation removes the p-type layers of vi) for a gate region of an n-channel HFET with an etchant that automatically stops at the p-type etch stop layer. Another etch operation removes the p-type etch stop layer to form a mesa at the p-type layer(s) of iv) which defines an interface to the gate region of the n-channel HFET, and a gate electrode is formed on such mesa.

The invention provides an optoelectronic device adapted to emit ultraviolet light, including an aluminum nitride single crystalline substrate, wherein the dislocation density of the substrate is less than about 10.sup.5 cm.sup.2 and the Full Width Half Maximum (FWHM) of the double axis rocking curve for the (002) and (102) crystallographic planes is less than about 200 arcsec; and an ultraviolet light-emitting diode structure overlying the aluminum nitride single crystalline substrate, the diode structure including a first electrode electrically connected to an n-type semiconductor layer and a second electrode electrically connected to a p-type semiconductor layer. In certain embodiments, the optoelectronic devices of the invention exhibit a reverse leakage current less than about 10.sup.5 A/cm.sup.2 at 10 V and/or an L80 of at least about 5000 hours at an injection current density of 28 A/cm.sup.2.

Bulk single crystals of AlN having a diameter greater than about 25 mm and dislocation densities of about 10,000 cm.sup.2 or less and high-quality AlN substrates having surfaces of any desired crystallographic orientation fabricated from these bulk crystals.

Discussed is a plurality of semiconductor light-emitting devices, wherein at least one of the semiconductor light-emitting devices includes: a first conductive electrode and a second conductive electrode; a first conductive semiconductor layer having the first conductive electrode arranged thereon; a second conductive semiconductor layer overlapping the first conductive semiconductor layer and having the second conductive electrode arranged thereon; an active layer arranged between the first conductive semiconductor layer and the second conductive semiconductor layer; an intermediate layer arranged on the second conductive semiconductor layer; a protrusion, made of an electro-polishable porous material, on the intermediate layer; and an undoped semiconductor layer arranged between the intermediate layer and the protrusion. The intermediate layer includes a first layer including second conductive impurities and a second layer having a higher concentration of the second conductive impurities than the first layer, wherein the first layer and the second layer are sequentially and repetitively stacked.

An infrared LED element includes: a conductive support substrate; and a semiconductor laminate and includes a material that can be lattice-matched with InP, in which the semiconductor laminate includes: a first semiconductor layer indicating a first conductivity type; an active layer disposed on an upper layer of the first semiconductor layer; a second semiconductor layer disposed on an upper layer of the active layer and indicating a second conductivity type; and a third semiconductor layer disposed on an upper layer of the second semiconductor layer and contains Al.sub.aGa.sub.bIn.sub.cAs indicating the second conductivity type, the third semiconductor layer has an uneven part on a surface opposite to a side on which the second semiconductor layer is positioned, and the third semiconductor layer has band gap energy lower than band gap energy of the second semiconductor layer and higher than band gap energy of the active layer.

In an embodiment a method for producing optoelectronic semiconductor chips includes A) growing an AlInGaAsP semiconductor layer sequence on a growth substrate along a growth direction, wherein the semiconductor layer sequence includes an active zone for radiation generation, and wherein the active zone is composed of a plurality of alternating quantum well layers and barrier layers, B) generating a structured masking layer, C) regionally intermixing the quantum well layers and the barrier layers by applying an intermixing auxiliary through openings of the masking layer into the active zone in at least one intermixing region and D) singulating the semiconductor layer sequence into sub-regions for the semiconductor chips, wherein the barrier layers in A) are grown from [(Al.sub.xGa.sub.1-x).sub.yIn.sub.1-y].sub.zP.sub.1-z with x0.5, and wherein the quantum well layers are grown in A) from [(Al.sub.aGa.sub.1-a).sub.bIn.sub.1-b].sub.cP.sub.1-c with o<a0.2.

Method for producing a light emitting semiconductor device comprising a zinc magnesium oxide based layer as active layer, wherein the zinc magnesium oxide based layer comprises an aluminum doped zinc magnesium oxide layer having the nominal composition Zn.sub.1-xMg.sub.xO with 1-350 ppm Al, wherein x is in the range of 0<x0.3. The invention further provides a method for the production of such aluminum doped zinc magnesium oxide, the method comprising heat treating a composition comprising Zn, Mg and Al with a predetermined composition at elevated temperatures, and subsequently annealing the heat treated composition to provide said aluminum doped zinc magnesium oxide.

In one embodiment, a light emitting device comprises a first light emitting part including at least one light emitting cell; a second light emitting part including a plurality of light emitting cells, wherein each of the light emitting cells include a light emitting structure and a first electrode layer disposed under the light emitting structure; a plurality of pads disposed on the light emitting cell of the first light emitting part, wherein the pads are electrically connected to each of the light emitting cells of the first and second light emitting parts; a plurality of connection layers, each connection layer extending from a region under the light emitting cell of the first light emitting part to a region under the plurality of light emitting cells of the second light emitting part; a second electrode layer disposed under the light emitting cells of the first and second light emitting parts; an insulating layer disposed between the first and second electrode layers; and at least one gap part disposed between the at least one light emitting cell of the first light emitting part and the plurality of light emitting cells of the second light emitting part, wherein each of the plurality of connection layers extends through a region under the gap part and is electrically connected to each of the plurality of the light emitting cells of the second light emitting part.