Abstract: In an embodiment, a III-V nitride semiconductor device comprises an AlGaN epitaxial layer and a metal electrode. The AlGaN epitaxial layer is a C-plane n-type or undoped layer, and the AlGaN epitaxial layer has an epitaxial surface consisting of one or more semi-polar planes. The metal electrode is directly formed on the one or more semi-polar planes.

Abstract: The present disclosure provides a LED structure which comprises an epitaxial layer, a current dispatching layer, a first electrode layer, and a second electrode layer. The epitaxial layer comprises sequentially disposed a high resistance buffer layer, a first GaN layer, an active layer, and a second GaN layer. A plurality of recesses are formed on a first surface of the epitaxial layer, each of the recesses has an opening on the first surface, penetrates the high resistance buffer layer, and contacts the first GaN layer. The current dispatching layer is disposed on the first surface of the epitaxial layer, and is disposed into the recesses for contacting the first GaN layer. The first electrode layer is disposed on the current dispatching layer, and the second electrode layer is disposed on a second surface of the epitaxial layer.

Abstract: A substrate structure is described, including a starting substrate, crystal piers on the starting substrate, and a mask layer. The mask layer covers an upper portion of the sidewall of each crystal pier, is connected between the crystal piers at its bottom, and is separated from the starting substrate by an empty space between the crystal piers. An epitaxial substrate structure is also described, which can be formed by growing an epitaxial layer over the above substrate structure form the crystal piers. The crystal piers may be broken after the epitaxial layer is grown.

Abstract: A substrate structure is described, including a starting substrate, crystal piers on the starting substrate, and a mask layer. The mask layer covers an upper portion of the sidewall of each crystal pier, is connected between the crystal piers at its bottom, and is separated from the starting substrate by an empty space between the crystal piers. An epitaxial substrate structure is also described, which can be formed by growing an epitaxial layer over the above substrate structure form the crystal piers. The crystal piers may be broken after the epitaxial layer is grown.

Abstract: A light emitting device with magnetic field includes a light emitting device, a thermal conductive material layer and a magnetic layer. The thermal conductive material layer is coupled with the light emitting device to dissipate heat generated by the light emitting device. The magnetic layer is coupled with thermal conductive material layer to produce a magnetic filed on the light emitting device.

Abstract: A multiwavelength quantum dot laser element is provided. A perpendicular stack of quantum dot active regions with different light emitting wavelengths is employed, and thickness, material composition, and quantum dot size of each of the quantum dot active regions are modulated, so as to form various laser oscillation conditions. When a current applied to the quantum dot laser element is larger than the start-oscillation current condition, lasers with different wavelengths are simultaneously obtained in each of the quantum dot active regions, thereby achieving the application of the multiwavelength quantum dot laser element.

Abstract: A light emitting device with magnetic field includes a light emitting device, a thermal conductive material layer and a magnetic layer. The thermal conductive material layer is coupled with the light emitting device to dissipate heat generated by the light emitting device. The magnetic layer is coupled with thermal conductive material layer to produce a magnetic filed on the light emitting device.

Abstract: A multiwavelength quantum dot laser element is provided. A perpendicular stack of quantum dot active regions with different light emitting wavelengths is employed, and thickness, material composition, and quantum dot size of each of the quantum dot active regions are modulated, so as to form various laser oscillation conditions. When a current applied to the quantum dot laser element is larger than the start-oscillation current condition, lasers with different wavelengths are simultaneously obtained in each of the quantum dot active regions, thereby achieving the application of the multiwavelength quantum dot laser element.

Abstract: A fabrication method of VCSEL is used to form a contact electrode on a VCSEL in a resonance cavity. A heavily doped layer is formed in a resonance cavity where the light intensity is the weakest. A Bragg reflector is etched while the etching stop point being above the heavily doped layer. Dopants are doped to form a high-carrier-concentration ohmic channel as a connection between an electrode and the heavily doped layer. Thereby, a contact electrode is formed on the VCSEL structure in the resonance cavity without the need of high etching precision.

Abstract: A fabrication method of VCSEL is used to form a contact electrode on a VCSEL in a resonance cavity. A heavily doped layer is formed in a resonance cavity where the light intensity is the weakest. A Bragg reflector is etched while the etching stop point being above the heavily doped layer. Dopants are doped to form a high-carrier-concentration ohmic channel as a connection between an electrode and the heavily doped layer. Thereby, a contact electrode is formed on the VCSEL structure in the resonance cavity without the need of high etching precision.