Abstract: Disclosed is an electrode assembly, a battery, and a battery pack and a vehicle including the same. In the electrode assembly, a first electrode, a second electrode, and a separator interposed therebetween are wound based on a winding axis to define a core and an outer circumference. The first electrode includes a first active material portion coated with an active material layer and a first uncoated portion not coated with an active material layer along a winding direction. At least a part of the first uncoated portion is defined as an electrode tab by itself. The first uncoated portion includes a first portion adjacent to the core of the electrode assembly, a second portion adjacent to the outer circumference of the electrode assembly, and a third portion interposed between the first portion and the second portion. The first portion or the second portion has a smaller height than the third portion in the winding axis direction.

Abstract: Disclosed is an electrode assembly, a battery, and a battery pack and a vehicle including the same. In the electrode assembly, a first electrode, a second electrode, and a separator interposed therebetween are wound based on an axis to define a core and an outer circumference. The first electrode includes an uncoated portion at a long side end thereof and exposed out of the separator along a winding axis direction of the electrode assembly. A part of the uncoated portion is bent in a radial direction of the electrode assembly to form a bending surface region that includes overlapping layers of the uncoated portion, and in a partial region of the bending surface region, the number of stacked layers of the uncoated portion is 10 or more in the winding axis direction of the electrode assembly.

Abstract: An electrode assembly, a battery, a battery pack and a vehicle including the same are provided. In the electrode assembly, the uncoated portion of an electrode includes a segment region divided into a plurality of segments, and the segment region includes a plurality of segment groups separated by a group separation pitch along a winding direction. One end of the electrode assembly includes a plurality of segment alignments. In winding turns corresponding to the plurality of segment alignments, group separation pitches of segment groups disposed in a same winding turn are substantially identical, and separation pitches of the segment groups is greater in a winding turn of a region adjacent to the outer circumference of the electrode assembly than in a winding turn of a region adjacent to the core of the electrode assembly.

Abstract: A light-emitting device includes a light-emitting structure including a first-conductivity-type nitride semiconductor layer on a substrate, an active layer on the first-conductivity-type nitride semiconductor layer, and a second-conductivity-type nitride semiconductor layer on the active layer, and a buffer layer between the substrate and the light-emitting structure. The buffer layer includes a plurality of voids. The plurality of voids extend vertically into the buffer layer from a surface of the buffer layer. The surface of the buffer layer is proximate to the light-emitting structure. The plurality of voids have different horizontal sectional areas.

Abstract: A light-emitting device includes a light-emitting structure including a first-conductivity-type nitride semiconductor layer on a substrate, an active layer on the first-conductivity-type nitride semiconductor layer, and a second-conductivity-type nitride semiconductor layer on the active layer, and a buffer layer between the substrate and the light-emitting structure. The buffer layer includes a plurality of voids. The plurality of voids extend vertically into the buffer layer from a surface of the buffer layer. The surface of the buffer layer is proximate to the light-emitting structure. The plurality of voids have different horizontal sectional areas.

Abstract: A semiconductor light emitting device includes a substrate formed of a first material; and a convex portion protruding from the substrate and including: a first layer formed of the first material as that of the substrate; and a second layer formed of a second material different from the first material and disposed on the first layer. A second height of the second layer is greater than a first height of the first layer.

Abstract: A light-emitting device includes a first conductive type semiconductor layer, a second conductive type semiconductor layer, and an active layer between the first conductive type semiconductor layer and the second conductive type semiconductor layer and having a plurality of V-pits. The light-emitting device further includes a layer-quality improvement layer between the first conductive type semiconductor layer and the second conductive type semiconductor layer and having a plurality of V-pits with substantially same size and shape as the plurality of V-pits of the active layer, wherein layer-quality improvement layer is a group III-V semiconductor layer including Al or In. Due to the improved layer quality, the luminescent quality of the light-emitting device is improved.

Abstract: A semiconductor light emitting device includes a substrate formed of a first material; and a convex portion protruding from the substrate and including: a first layer formed of the first material as that of the substrate; and a second layer formed of a second material different from the first material and disposed on the first layer. A second height of the second layer is greater than a first height of the first layer.

Abstract: A light-emitting device includes a first conductive type semiconductor layer, a second conductive type semiconductor layer, and an active layer between the first conductive type semiconductor layer and the second conductive type semiconductor layer and having a plurality of V-pits. The light-emitting device further includes a layer-quality improvement layer between the first conductive type semiconductor layer and the second conductive type semiconductor layer and having a plurality of V-pits with substantially same size and shape as the plurality of V-pits of the active layer, wherein layer-quality improvement layer is a group III-V semiconductor layer including Al or In. Due to the improved layer quality, the luminescent quality of the light-emitting device is improved.

Abstract: An apparatus for evaluating the quality of a crystal includes an optical device that measures a surface reflectance of a wafer in which a V-pit is formed; and a data processing unit that calculates a threading dislocation density by calculating a difference in surface reflectance of the wafer that is measured by the optical device.

Abstract: An apparatus for evaluating the quality of a crystal includes an optical device that measures a surface reflectance of a wafer in which a V-pit is formed; and a data processing unit that calculates a threading dislocation density by calculating a difference in surface reflectance of the wafer that is measured by the optical device.

Abstract: A semiconductor light emitting device may include a base semiconductor layer formed on a substrate and having defect regions therein; cavities disposed in regions corresponding to the defect regions on the base semiconductor layer; a capping layer disposed to cover at least one region of the base semiconductor layer and the cavities; and a light emitting structure disposed on the capping layer and including a first conductivity-type semiconductor layer, an active layer, and a second conductivity-type semiconductor layer. Lattice defects formed in the light emitting structure may be reduced to enhance luminous efficiency.