摘要:
An optical semiconductor device with a multiple quantum well structure, in which well layers and barrier layers comprising various types of semiconductor layers are alternately layered, in which device well layers (6a) of a first composition based on a nitride semiconductor material with a first electron energy and barrier layers (6b) of a second composition of a nitride semiconductor material with electron energy which is higher in comparison with the first electron energy are provided, followed, seen in the direction of growth, by a radiation-active quantum well layer (6c), for which the essentially non-radiating well layers (6a) and the barrier layers (6b) arranged in front form a superlattice.
摘要:
A seed crystal assembly for producing monocrystals and a method for producing SiC monocrystals or monocrystalline SiC layers include a seed crystal with a surface having a first partial region intended as a crystallization surface for a monocrystal grown out of a gas phase and a second partial region with a coating that is chemically resistant to the seed crystal and to the gas phase and does not melt at the growth temperatures. As a result, thermal degradation of the seed crystal is avoided and the quality of the monocrystals which are produced is increased.
摘要:
A radiation-emitting semiconductor component has an improved radiation efficiency. The semiconductor component has a multilayer structure with an active layer for generating radiation within the multilayer structure and also a window having a first and a second main surface. The multi-layer structure adjoins the first main surface of the window. At least one recess, such as a trench or a pit, is formed in the window from the second main surface for the purpose of increasing the radiation efficiency. The recess preferably has a trapezoidal cross section tapering toward the first main surface and can be produced for example by sawing into the window.
摘要:
An optical semiconductor device with a multiple quantum well structure, in which well layers and barrier layers comprising various types of semiconductor layers are alternately layered, in which device well layers (6a) of a first composition based on a nitride semiconductor material with a first electron energy and barrier layers (6b) of a second composition of a nitride semiconductor material with electron energy which is higher in comparison with the first electron energy are provided, followed, seen in the direction of growth, by a radiation-active quantum well layer (6c), for which the essentially non-radiating well layers (6a) and the barrier layers (6b) arranged in front form a superlattice.
摘要:
An optical semiconductor device with a multiple quantum well structure, in which well layers and barrier layers comprising various types of semiconductor layers are alternately layered, in which device well layers (6a) of a first composition based on a nitride semiconductor material with a first electron energy and barrier layers (6b) of a second composition of a nitride semiconductor material with electron energy which is higher in comparison with the first electron energy are provided, followed, seen in the direction of growth, by a radiation-active quantum well layer (6c), for which the essentially non-radiating well layers (6a) and the barrier layers (6b) arranged in front form a superlattice.
摘要:
A radiation-emitting semiconductor chip (1) having a semiconductor layer sequence (3) comprising at least one active layer (2) that generates an electromagnetic radiation, and having a passivation layer (12) arranged on the radiation-emerging side of the semiconductor layer sequence (3), it being possible to set the degree of transmission of the semiconductor chip by means of the passivation layer.
摘要:
A method for producing cubic SiC monocrystals includes dissolving SiC powder or other starting material in a solvent at high overpressures and growing the monocrystals on a seed crystal.
摘要:
An optical semiconductor device with a multiple quantum well structure, in which well layers and barrier layers comprising various types of semiconductor layers are alternately layered, in which device well layers (6a) of a first composition based on a nitride semiconductor material with a first electron energy and barrier layers (6b) of a second composition of a nitride semiconductor material with electron energy which is higher in comparison with the first electron energy are provided, followed, seen in the direction of growth, by a radiation-active quantum well layer (6c), for which the essentially non-radiating well layers (6a) and the barrier layers (6b) arranged in front form a superlattice.
摘要:
A reaction chamber (2) is enclosed by a gas-tight wall (20), made of silicon carbide obtained by a CVD process at least on the inside (21) facing the reaction chamber (2). At least part of the silicon carbide of the wall (20) is sublimated and grown on a seed crystal (3) as a silicon carbide monocrystal (4).
摘要:
SiC single crystals are produced in a reaction chamber, in which there is a seed crystal for the separation of a SiC single crystal from the gas phase. The reaction chamber is connected to a storage chamber, which is at least partly filled with a supply of SiC, by a gas channel with a predetermined cross-section for conveying the SiC in the gas phase. The supply of SiC is sublimated in a heating device and a temperature gradient is adjusted in the reaction chamber. It is, thus, possible to produce SiC single crystals with any desired cross-sectional area and of high crystalline quality and single-crystal yield, because the conveyance rate of the gas molecules can be precisely adjusted.