Heterostructures include a layer of a two-dimensional material placed on a multiferroic layer. An ordered array of differing polarization domains in the multiferroic layer produces corresponding domains having differing properties in the two-dimensional material. When the multiferroic layer is ferroelectric, the ferroelectric polarization domains in the layer produce local electric fields that penetrate the two-dimensional material. The local electric fields modulate the charge carriers and carrier density on a nanometer length scale, resulting in the formation of lateral p-n or p-i-n junctions, and variations thereof appropriate for device functions.

In some embodiments, a light emitting structure comprises a layered semiconductor stack comprising a first set of doped layers, a second layer, a light emitting layer positioned between the first set of doped layers and the second layer, and an electrical contact to the first set of doped layers. The first set of doped layers can comprise a first sub-layer, a second sub-layer, and a third sub-layer, wherein the third sub-layer is adjacent to the light emitting layer. The electrical contact can be coupled to the second sub-layer. The first, second and third sub-layers can be doped n-type, and an electrical conductivity of the second sub-layer can be higher than an electrical conductivity of the first and third sub-layers. The first, second and third sub-layers, the light emitting layer, and the second layer can each comprise a superlattice.

An LED array comprises a first mesa comprising a top surface, at least a first LED including a first p-type layer, a first n-type layer and a first color active region and a tunnel junction on the first LED, a second n-type layer on the tunnel junction, the second n-type layer comprising at least one n-type III-nitride layer with >10% Al mole fraction and at least one n-type III-nitride layer with <10% Al mole fraction. The LED array further comprises an adjacent mesa comprising a top surface, the first LED, a second LED including the second n-type layer, a second p-type layer and a second color active region. A first trench separates the first mesa and the adjacent mesa, cathode metallization in the first trench and in electrical contact with the first and the second color active regions of the adjacent mesa, and anode metallization contacts on the n-type layer of the first mesa and on the anode layer of the adjacent mesa. The devices and methods for their manufacture include a thin film transistor (TFT).

A light emitting device according to an exemplary embodiment includes a first light emission region and a second light emission region. The first and second light emission regions include a first conductivity type semiconductor layer, a second conductivity type semiconductor layer, and an active region formed between the first conductivity type semiconductor layer and the second conductivity type semiconductor layer, respectively, an area of the first light emission region is larger than an area of the second emission region, and at least one of the first emission region or the second emission region emits light of a plurality of peak wavelengths.

A light emitting apparatus includes an electrode and a laminated structure. The laminated structure includes an n-type first semiconductor layer, a light emitting layer, a p-type second semiconductor layer, a tunnel junction layer, and an n-type third semiconductor layer. The electrode is electrically connected to the first semiconductor layer. The first semiconductor layer, the light emitting layer, the second semiconductor layer, the tunnel junction layer, and the third semiconductor layer are arranged in a presented order. The light emitting layer and the first semiconductor layer form a columnar section.

A light emitting apparatus includes an electrode and a laminated structure. The laminated structure includes an n-type first semiconductor layer, a light emitting layer, a p-type second semiconductor layer, a tunnel junction layer, and an n-type third semiconductor layer. The electrode is electrically connected to the first semiconductor layer. The first semiconductor layer, the light emitting layer, the second semiconductor layer, the tunnel junction layer, and the third semiconductor layer are arranged in a presented order. The light emitting layer and the first semiconductor layer form a columnar section.

A device emitting mid-infrared light that comprises a semiconductor substrate of GaSb or closely related material. The device can also comprise epitaxial heterostructures of InAs, GaAs, AlSb, and related alloys forming light emitting structures cascaded by tunnel junctions. Further, the device can comprise light emission from the front, epitaxial side of the substrate.

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 stacked body includes a long side and a short side in a top view. The long side extends in a first direction. The short side extends in a second direction orthogonal to the first direction. The short side is shorter than the long side. A light emission peak wavelength of a first active layer is different from a light emission peak wavelength of a second active layer. A first n-type layer includes a first n-side contact portion contacting a first electrode. A second n-type layer includes a second n-side contact portion contacting a second electrode. In a top view, a center of the first n-side contact portion is separated from a first line that passes through a center of the second n-side contact portion and is parallel to the first direction.

Disclosed are an optoelectronic device and a preparation method thereof. The optoelectronic device includes a first semiconductor layer, an active layer, and a second semiconductor layer stacked in sequence. The conductivity type of the first semiconductor layer is opposite to that of the second semiconductor layer, and the second semiconductor layer is provided with a layer of nano-diamond structure, and the nano-diamond structure has the same conductivity type as the second semiconductor layer. The method for preparing the optoelectronic device is used to make the optoelectronic device. In the present application, by providing a layer of nano-diamond structure in the second semiconductor layer, the absorption of UV light emitted by the active layer can be effectively avoided, and the beneficial effect of greatly improving the light extraction efficiency of the UV LED can be achieved.