Abstract:
A heat exchanger is provided with a header tank having therein a circulation portion in which fluid flows, and multiple tubes which are stacked in a longitudinal direction of the header tank. The circulation portion is communicated with interiors of the tubes, and partitioned into an inlet side passage and other passages. An inflow port member is arranged at a longitudinal-direction end of the inlet side passage, and provided with multiple openings for causing at least a mainstream flow and a substream flow of fluid introduced toward the tubes. The mainstream flow is substantially evenly flow-divided by the substream flow.
Abstract:
An ink fountain apparatus for a rotary printing press includes an ink fountain, an intermediate ink dam, and press unit for simultaneously pressing the intermediate ink dam toward the outer surface of the fountain roller and toward the upper surface of the bottom plate. A width of the first surface close to the boundary portion in the axial direction of the fountain roller is set to be smaller than a width of the first surface arranged upstream of the fountain roller in a rotational direction from the boundary portion in the axial direction of the fountain roller.
Abstract:
The active region of a long-wavelength light emitting device is made by providing an organometallic vapor phase epitaxy (OMVPE) reactor, placing a substrate wafer capable of supporting growth of indium gallium arsenide nitride in the reactor, supplying a Group III–V precursor mixture comprising an arsenic precursor, a nitrogen precursor, a gallium precursor, an indium precursor and a carrier gas to the reactor and pressurizing the reactor to a sub-atmospheric elevated growth pressure no higher than that at which a layer of indium gallium arsenide layer having a nitrogen fraction commensurate with light emission at a wavelength longer than 1.2 μm is deposited over the substrate wafer.
Abstract:
A light emitting device in accordance with an embodiment of the present invention includes a first semiconductor layer of a first conductivity type having a first surface, and an active region formed overlying the first semiconductor layer. The active region includes a second semiconductor layer which is either a quantum well layer or a barrier layer. The second semiconductor layer is formed from a semiconductor alloy having a composition graded in a direction substantially perpendicular to the first surface of the first semiconductor layer. The light emitting device also includes a third semiconductor layer of a second conductivity type formed overlying the active region.
Abstract:
An ink fountain apparatus for a rotary printing press includes an ink fountain, an intermediate ink dam, and press unit for simultaneously pressing the intermediate ink dam toward the outer surface of the fountain roller and toward the upper surface of the bottom plate. A width of the first surface close to the boundary portion in the axial direction of the fountain roller is set to be smaller than a width of the first surface arranged upstream of the fountain roller in a rotational direction from the boundary portion in the axial direction of the fountain roller.
Abstract:
A method and system for growing a layer of semiconductor material is disclosed. The method can be used to grow a layer of a semiconducting material comprising at least one Group III element, nitrogen and at least one other Group V element as constituent elements thereof, the method comprising providing a reactor and supplying precursors to the reactor. The precursors include a precursor for each of the at least one Group III element, a precursor for the nitrogen, a precursor for each of the at least one Group V element other than nitrogen, and a precursor for an element having a stronger bond strength with nitrogen than each of the at least one Group III element has with nitrogen. The method can be implemented in, for example, a metal organic chemical vapor deposition (MOCVD) reactor.
Abstract:
Light-emitting devices are described. One example of a light-emitting device includes a first barrier layer and a second barrier layer, and a quantum well layer located between the first and second barrier layers. The first and second barrier layers are composed of gallium arsenide, and the quantum well layer is composed of indium gallium arsenide nitride. A first layer is located between the quantum well layer and the first barrier layer. The first layer has a bandgap energy between that of the first barrier layer and that of the quantum well layer. Another example of a light-emitting device includes a quantum well and a carrier capture element adjacent the quantum well. The carrier capture element increases the effective carrier capture cross-section of the quantum well.
Abstract:
A method for fabricating a light-emitting semiconductor device including a III-Nitride quantum well layer includes selecting a facet orientation of the quantum well layer to control a field strength of a piezoelectric field and/or a field strength of a spontaneous electric field in the quantum well layer, and growing the quantum well layer with the selected facet orientation. The facet orientation may be selected to reduce the magnitude of a piezoelectric field and/or the magnitude of a spontaneous electric field, for example. The facet orientation may also be selected to control or reduce the magnitude of the combined piezoelectric and spontaneous electric field strength.
Abstract:
The nitride semiconductor layer structure comprises a buffer layer and a composite layer on the buffer layer. The buffer layer is a layer of a low-temperature-deposited nitride semiconductor material that includes AlN. The composite layer is a layer of a single-crystal nitride semiconductor material that includes AlN. The composite layer includes a first sub-layer adjacent the buffer layer and a second sub-layer over the first sub-layer. The single-crystal nitride semiconductor material of the composite layer has a first AlN molar fraction in the first sub-layer and has a second AlN molar fraction in the second sub-layer. The second AlN molar fraction is greater than the first AlN molar fraction. The nitride semiconductor laser comprises a portion of the above-described nitride semiconductor layer structure, and additionally comprises an optical waveguide layer over the composite layer and an active layer over the optical waveguide layer.
Abstract:
Several methods for producing an active region for a long wavelength light emitting device are disclosed. In one embodiment, the method comprises placing a substrate in an organometallic vapor phase epitaxy (OMVPE) reactor, the substrate for supporting growth of an indium gallium arsenide nitride (InGaAsN) film, supplying to the reactor a group-III-V precursor mixture comprising arsine, dimethylhydrazine, alkyl-gallium, alkyl-indium and a carrier gas, where the arsine and the dimethylhydrazine are the group-V precursor materials and where the percentage of dimethylhydrazine substantially exceeds the percentage of arsine, and pressurizing the reactor to a pressure at which a concentration of nitrogen commensurate with light emission at a wavelength longer than 1.2 um is extracted from the dimethylhydrazine and deposited on the substrate.