摘要:
A method for fabricating a III-nitride based semiconductor device, including (a) growing one or more buffer layers on or above a semi-polar or non-polar GaN substrate, wherein the buffer layers are semi-polar or non-polar III-nitride buffer layers; and (b) doping the buffer layers so that a number of crystal defects in III-nitride device layers formed on or above the doped buffer layers is not higher than a number of crystal defects in III-nitride device layers formed on or above one or more undoped buffer layers. The doping can reduce or prevent formation of misfit dislocation lines and additional threading dislocations. The thickness and/or composition of the buffer layers can be such that the buffer layers have a thickness near or greater than their critical thickness for relaxation. In addition, one or more (AlInGaN) or III-nitride device layers can be formed on or above the buffer layers.
摘要:
A nonpolar III-nitride film grown on a miscut angle of a substrate, in order to suppress the surface undulations, is provided. The surface morphology of the film is improved with a miscut angle towards an α-axis direction comprising a 0.15° or greater miscut angle towards the α-axis direction and a less than 30° miscut angle towards the α-axis direction.
摘要:
Disclosed is an improved light-emitting device for an AC power operation. An AC light-emitting device according to the present invention employs a variety of means by which light emission time is prolonged during a ½ cycle in response to a phase change of an AC power source and a flicker effect can be reduced. For example, the means may be switching blocks respectively connected to nodes between the light emitting cells, switching blocks connected to a plurality of arrays, or a delay phosphor. Further, there is provided an AC light-emitting device, wherein a plurality of arrays having the different numbers of light emitting cells are employed to increase light emission time and to reduce a flicker effect.
摘要:
Disclosed is an improved light-emitting device for an AC power operation. A conventional light emitting device employs an AC light-emitting diode having arrays of light emitting cells connected in reverse parallel. The arrays in the prior art alternately repeat on/off in response to a phase change of an AC power source, resulting in short light emission time during a ½ cycle and the occurrence of a flicker effect. An AC light-emitting device according to the present invention employs a variety of means by which light emission time is prolonged during a ½ cycle in response to a phase change of an AC power source and a flicker effect can be reduced. For example, the means may be switching blocks respectively connected to nodes between the light emitting cells, switching blocks connected to a plurality of arrays, or a delay phosphor. Further, there is provided an AC light-emitting device, wherein a plurality of arrays having the different numbers of light emitting cells are employed to increase light emission time and to reduce a flicker effect.
摘要:
A method of forming a p-type compound semiconductor layer includes increasing a temperature of a substrate loaded into a reaction chamber to a first temperature. A source gas of a Group III element, a source gas of a p-type impurity, and a source gas of nitrogen containing hydrogen are supplied into the reaction chamber to grow the p-type compound semiconductor layer. Then, the supply of the source gas of the Group III element and the source gas of the p-type impurity is stopped and the temperature of the substrate is lowered to a second temperature. The supply of the source gas of nitrogen containing hydrogen is stopped and drawn out at the second temperature, and the temperature of the substrate is lowered to room temperature using a cooling gas. Accordingly, hydrogen is prevented from bonding to the p-type impurity in the p-type compound semiconductor layer.
摘要:
Techniques for processing materials in supercritical fluids including processing in a capsule disposed within a high-pressure apparatus enclosure are disclosed. The disclosed techniques are useful for growing crystals of GaN, AlN, InN, and their alloys, including InGaN, AlGaN, and AlInGaN for the manufacture of bulk or patterned substrates, which in turn can be used to make optoelectronic devices, lasers, light emitting diodes, solar cells, photoelectrochemical water splitting and hydrogen generation devices, photodetectors, integrated circuits, and transistors.