An optoelectronic semiconductor chip includes a semiconductor layer sequence having an active layer that generates radiation and at least one n-doped layer adjoining the active layer, the semiconductor layer sequence is based on AlInGaN or on InGaN, one or a plurality of central layers composed of AlGaN each having thicknesses of 25 nm to 200 nm are grown at a side of the n-doped layer facing away from a carrier substrate, a coalescence layer of doped or undoped GaN having a thickness of 300 nm to 1.2 m is formed at a side of the central layer or one of the central layers facing away from the carrier substrate, a roughening extends from the coalescence layer as far as or into the n-doped layer, a radiation exit area of the semiconductor layer stack is formed partly by the coalescence layer, and the central layer is exposed in places.

The present disclosure provides a light emitting element, wherein each of first and second semiconductor layers has first and second pits disposed therein, wherein the first pit has a first depth and the second pit has a second depth smaller than the first depth, and the first and second pits are coupled to each other, wherein a density of the second pits in an upper portion of the second semiconductor layer is lower than a density of the second pits in an upper portion of the first semiconductor layer, wherein a density of the first pits in the upper portion of the second semiconductor layer is equal to a density of the first pits in the upper portion of the first semiconductor layer.

A light-emitting diode comprises a substrate; a semiconductor stack on the substrate, wherein the semiconductor stack comprises a first semiconductor layer, an active layer for emitting a light, and a second semiconductor layer; a first oxide layer on the semiconductor stack, wherein the first oxide layer has a top surface opposite to the semiconductor stack, and the top surface comprises a first region and a second region; and a first pad on the second region; wherein the first region is rougher than the second region, wherein the first oxide layer comprises an impurity, and a concentration of the impurity of the first oxide layer in the first region is higher than that of the impurity of the first oxide layer in the second region.

An improved heterostructure for an optoelectronic device is provided. The heterostructure includes an active region, an electron blocking layer, and a p-type contact layer. The p-type contact layer and electron blocking layer can be doped with a p-type dopant. The dopant concentration for the electron blocking layer can be at most ten percent the dopant concentration of the p-type contact layer. A method of designing such a heterostructure is also described.

A III-nitride light emitting layer is disposed between an n-type region and a p-type region in a double heterostructure. At least a portion of the III-nitride light emitting layer has a graded composition.

A III-nitride light emitting layer is disposed between an n-type region and a p-type region in a double heterostructure. At least a portion of the III-nitride light emitting layer has a graded composition.

Provided is a nitride semiconductor light emitting element in which deep-level light emission is suppressed, monochromaticity is improved, and light is emitted in a high-efficiency manner A nitride semiconductor light emitting element having a light-emitting layer between an n-type nitride semiconductor layer and a p-type nitride semiconductor layer, wherein the n-type nitride semiconductor layer contains Al.sub.nGa.sub.1-nN (0<n1), and has a C concentration of 110.sup.17/cm.sup.3 or less.

A method for manufacturing a light emitting device includes a) forming a first light confinement layer having a plurality of openings on or above one main surface of an oriented polycrystalline substrate, said oriented polycrystalline substrate including a plurality of oriented crystal grains; b) stacking an n-type layer, an active layer, and a p-type layer; c) forming a second light confinement layer on said first light confinement layer so that said second light confinement layer covers said plurality of first columnar structures and said second columnar structure; d) forming a transparent conductive film on said second light confinement layer; e) forming a pad electrode on said transparent conductive film; and f) forming a cathode electrode electrically connected to ends of said plurality of first columnar structures closer to said oriented polycrystalline substrate.

A method of growing an AlGaN semiconductor material utilizes an excess of Ga above the stoichiometric amount typically used. The excess Ga results in the formation of band structure potential fluctuations that improve the efficiency of radiative recombination and increase light generation of optoelectronic devices, in particular ultraviolet light emitting diodes, made using the method. Several improvements in UV LED design and performance are also provided for use together with the excess Ga growth method. Devices made with the method can be used for water purification, surface sterilization, communications, and data storage and retrieval.

A solution for fabricating a semiconductor structure is provided. The semiconductor structure includes a plurality of semiconductor layers grown over a substrate using a set of epitaxial growth periods. During each epitaxial growth period, a first semiconductor layer having one of: a tensile stress or a compressive stress is grown followed by growth of a second semiconductor layer having the other of: the tensile stress or the compressive stress directly on the first semiconductor layer.