Abstract: Disclosed herein are a material layer stack, a light emitting element, a light emitting package, and a method of fabricating a light emitting element. The material layer stack includes: a substrate having a first lattice constant; and a semiconductor layer grown on the substrate, the semiconductor layer having a second lattice constant that is different from the first lattice constant. Using the material layer stack, a light emitting element having a low leakage current, a low operation voltage, and an excellent luminous efficiency can be obtained.

Abstract: Disclosed herein are a material layer stack, a light emitting element, a light emitting package, and a method of fabricating a light emitting element. The material layer stack includes: a substrate having a first lattice constant; and a semiconductor layer grown on the substrate, the semiconductor layer having a second lattice constant that is different from the first lattice constant. Using the material layer stack, a light emitting element having a low leakage current, a low operation voltage, and an excellent luminous efficiency can be obtained.

Abstract: A method of manufacturing a semiconductor light-emitting device is provided. The method includes operations of forming a first conductive type semiconductor layer on a substrate; forming a V-pit in the first conductive type semiconductor layer; forming a defect decreasing structure in and over the V-pit; and forming a residual first conductive type semiconductor layer on the defect decreasing structure. By using the method, an excellent-quality semiconductor light-emitting device having a reduced crystal defect may be inexpensively manufactured.

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 vertical light-emitting device includes: a substrate; a first electrode disposed on a bottom surface of the substrate; a reflection layer disposed on a top surface of the substrate; a current spreading layer disposed on the reflection layer and comprising a groove having a width narrower toward a top portion thereof; a light generation layer disposed on the current spreading layer; and a second electrode disposed on the light generation layer.