Abstract: A light emitting diode including a GaN substrate, a first type semiconductor layer, a light emitting layer, a second type semiconductor layer, a first electrode, and a second electrode is provided. The GaN substrate has a first surface and a second surface opposite thereto, and the second surface has a plurality of protuberances, the height of the protuberance is h ?m and the distribution density of the protuberance on the second surface is d cm?2, wherein 9.87×107?h2d, and h?1.8. The first type semiconductor is disposed on the first surface of the GaN substrate. The light emitting layer is disposed on a partial region of the first semiconductor layer, and the wavelength of the light emitted by the light emitting layer is from 375 nm to 415 nm. The second semiconductor layer is disposed on the light emitting layer.

Abstract: A light emitting diode including a GaN substrate, a first type semiconductor layer, a light emitting layer, a second type semiconductor layer, a first electrode, and a second electrode is provided. The GaN substrate has a first surface and a second surface opposite thereto, and the second surface has a plurality of protuberances, the height of the protuberance is h ?m and the distribution density of the protuberance on the second surface is d cm?2, wherein 9.87×107?h2d, and h?1.8. The first type semiconductor is disposed on the first surface of the GaN substrate. The light emitting layer is disposed on a partial region of the first semiconductor layer, and the wavelength of the light emitted by the light emitting layer is from 375 nm to 415 nm. The second semiconductor layer is disposed on the light emitting layer.

Abstract: A nitride semiconductor LED device including an N-type doped layer, an active layer and a P-type doped layer is provided. The active layer is disposed on the N-type doped layer and includes at least one quantum well structure. The quantum well structure includes two quantum barrier layers and a quantum well sandwiched between the quantum barrier layers. The quantum barrier layer is a super-lattice structure including a quaternary nitride semiconductor. The P-type doped layer is disposed on the active layer.

Abstract: A nitride semiconductor LED device including an N-type doped layer, an active layer and a P-type doped layer is provided. The active layer is disposed on the N-type doped layer and includes at least one quantum well structure. The quantum well structure includes two quantum barrier layers and a quantum well sandwiched between the quantum barrier layers. The quantum barrier layer is a super-lattice structure including a quaternary nitride semiconductor. The P-type doped layer is disposed on the active layer.

Abstract: A light emitting device is provided, which includes a light-emitting structure having an active layer and a magnetic material. The active layer includes at least one quantum well structure, and a thickness of at least one of the quantum well structure is greater than or substantially equal to 1.2 nm at room temperature. The magnetic material is coupled with the light-emitting structure to produce a magnetic field perpendicular to a surface of the active layer in the light-emitting structure.