Abstract: A system capable of detecting and/or sterilizing surface(s) of an object using ultraviolet radiation is provided. The system can include a disinfection chamber and/or handheld ultraviolet unit, which includes ultraviolet sources for inducing fluorescence in a contaminant and/or sterilizing a surface of an object. The object can comprise a protective suit, which is worn by a user and also can include ultraviolet sources for disinfecting air prior to the air entering the protective suit. The system can be implemented as a multi-tiered system for protecting the user and others from exposure to the contaminant and sterilizing the protective suit after exposure to an environment including the contaminant.

Abstract: A diffusive illuminator is provided. The diffusive illuminator includes a set of light sources and a light guiding structure including a plurality of layers. At least some of the layers can be formed of a fluoropolymer and at least one layer can be formed of a transparent fluid. The light guiding structure also includes an emission surface through which diffused light exits. The light guiding structure can further include diffusive elements associated with at least one of the plurality of layers. Each diffusive element can diffuse the light to within forty percent of Lambertian distribution. The diffusive elements can be arranged based on a desired uniformity of the diffused light at a target distance corresponding to a surface to be illuminated. The diffusive illuminator can emit ultraviolet light, and can be implemented as part of a disinfection system.

Abstract: A semiconductor structure comprising a buffer structure and a set of semiconductor layers formed adjacent to a first side of the buffer structure is provided. The buffer structure can have an effective lattice constant and a thickness such that an overall stress in the set of semiconductor layers at room temperature is compressive and is in a range between approximately 0.1 GPa and 2.0 GPa. The buffer structure can be grown using a set of growth parameters selected to achieve the target effective lattice constant a, control stresses present during growth of the buffer structure, and/or control stresses present after the semiconductor structure has cooled.

Abstract: A solid-state light source (SSLS) structure with integrated control. In one embodiment, a SSLS control circuit can be integrated with a SSLS structure formed from a multiple of SSLSs. The SSLS control circuit controls the total operating current of the SSLS structure to within a predetermined total operating current limit by selectively limiting the current in individual SSLSs or in groups of SSLSs as each are turned on according to a sequential order. The SSLS control circuit limits the current in each of the individual SSLSs or groups of SSLSs as function of the saturation current of the SSLSs. In one embodiment, the individual SSLSs or groups of SSLSs has a turn on voltage corresponding to a voltage causing a preceding SSLS or group of SSLSs in the sequential order to saturate current.

Abstract: A multi-layered contact to a semiconductor structure and a method of making is described. In one embodiment, the contact includes a discontinuous Chromium layer formed over the semiconductor structure. A discontinuous Titanium layer is formed directly on the Chromium layer, wherein portions of the Titanium layer extend into at least some of the discontinuous sections of the Chromium layer. A discontinuous Aluminum layer is formed directly on the Chromium layer, wherein portions of the Aluminum layer extend into at least some of the discontinuous sections of the Titanium layer and the Chromium layer.

Abstract: A light emitting heterostructure including a partially relaxed semiconductor layer is provided. The partially relaxed semiconductor layer can be included as a sublayer of a contact semiconductor layer of the light emitting heterostructure. A dislocation blocking structure also can be included adjacent to the partially relaxed semiconductor layer.

Abstract: A light guiding structure is provided. The structure includes an anodized aluminum oxide (AAO) layer and a fluoropolymer layer located immediately adjacent to a surface of the AAO layer. Light propagates through the AAO layer in a direction substantially parallel to the fluoropolymer layer. An optoelectronic device can be coupled to a surface of the AAO layer, and emit/sense light propagating through the AAO layer. Solutions for fabricating the light guiding structure are also described.

Abstract: A system for sterilizing at least one surface of an object is provided. The system includes a set of ultraviolet radiation sources and a set of wave guiding structures configured to direct ultraviolet radiation having a set of target attributes to a desired location on at least one surface of the object. The set of wave guiding structures can include at least one ultraviolet reflective surface having an ultraviolet reflection coefficient of at least thirty percent. Furthermore, the system can include a computer system for operating the ultraviolet radiation sources to deliver a target dose of ultraviolet radiation to the at least one target surface of the object.

Abstract: A solution in which an ultraviolet radiation source is mounted on a flexible substrate is provided. The flexible substrate is capable of having a deformation curvature of at least 0.1 inverse meters. The flexible substrate may be incorporated within an existing enclosure or included in the enclosure. The flexible substrate can be utilized as part of a solution for disinfecting one or more items located within the enclosure. In this case, while the items are within the enclosure, ultraviolent radiation is generated and directed at the items. Wiring for the ultraviolet radiation source can be embedded within the flexible substrate and the flexible substrate can have at least one of: a wave-guiding structure, an ultraviolet absorbing surface, or an ultraviolet reflective surface. A control system can be utilized to manage generation of the ultraviolet radiation within the enclosure.

Abstract: A device having a layer with a patterned surface for improving the growth of semiconductor layers, such as group III nitride-based semiconductor layers with a high concentration of aluminum, is provided. The patterned surface can include a substantially flat top surface and a plurality of stress reducing regions, such as openings. The substantially flat top surface can have a root mean square roughness less than approximately 0.5 nanometers, and the stress reducing regions can have a characteristic size between approximately 0.1 microns and approximately five microns and a depth of at least 0.2 microns. A layer of group-III nitride material can be grown on the first layer and have a thickness at least twice the characteristic size of the stress reducing regions.

Abstract: A solution for designing and/or fabricating a structure including a quantum well and an adjacent barrier is provided. A target band discontinuity between the quantum well and the adjacent barrier is selected to coincide with an activation energy of a dopant for the quantum well and/or barrier. For example, a target valence band discontinuity can be selected such that a dopant energy level of a dopant in the adjacent barrier coincides with a valence energy band edge for the quantum well and/or a ground state energy for free carriers in a valence energy band for the quantum well. Additionally, a target doping level for the quantum well and/or adjacent barrier can be selected to facilitate a real space transfer of holes across the barrier. The quantum well and the adjacent barrier can be formed such that the actual band discontinuity and/or actual doping level(s) correspond to the relevant target(s).

Abstract: A solid-state light source (SSLS) with light modulation control is described. A SSLS device can include a main p-n junction region configured for recombination of electron-hole pairs for light emission. A supplementary p-n junction region is proximate the main p-n junction region to supplement the recombination of electron-hole pairs, wherein the supplementary p-n junction region has a smaller electron-hole life time than the electron-hole life time of the main p-n junction region. The main p-n junction region and the supplementary p-n junction region operate cooperatively in a light emission state and a light turn-off-state. In one embodiment, the recombination of electron-hole pairs occurs in the main p-n junction region during a light emission state, and the recombination of electron-hole pairs occurs in the supplementary p-n junction region light during the light turn off-state.

Abstract: A semiconductor heterostructure for an optoelectronic device includes a base semiconductor layer having one or more semiconductor heterostructure mesas located thereon. One or more of the mesas can include a set of active regions having multiple main peaks of radiative recombination at differing wavelengths. For example, a mesa can include two or more active regions, each of which has a different wavelength for the corresponding main peak of radiative recombination. The active regions can be configured to be operated simultaneously or can be capable of independent operation. A system can include one or more optoelectronic devices, each of which can be operated as an emitter or a detector.

Abstract: A solution for disinfecting an area using ultraviolet radiation is provided. The solution can include an enclosure including at least one ultraviolet transparent window and a set of ultraviolet radiation sources located adjacent to the at least one ultraviolet transparent window. The set of ultraviolet radiation sources can be configured to generate ultraviolet radiation directed through the at least one ultraviolet transparent window. An input unit can be located on the enclosure and configured to generate an electrical signal in response to pressure applied to the enclosure. A control unit can be configured to manage the ultraviolet radiation by monitoring the electrical signal generated by the input unit and controlling, based on the monitoring, the ultraviolet radiation generated by the set of ultraviolet radiation sources.

Abstract: An approach for controlling ultraviolet intensity over a surface of a light sensitive object is described. Aspects involve using ultraviolet radiation with a wavelength range that includes ultraviolet-A and ultraviolet-B radiation to irradiate the surface. Light sensors measure light intensity at the surface, wherein each sensor measures light intensity in a wavelength range that corresponds to a wavelength range emitted from at least one of the sources. A controller controls the light intensity over the surface by adjusting the power of the sources as a function of the light intensity measurements. The controller uses the light intensity measurements to determine whether each source is illuminating the surface with an intensity that is within an acceptable variation with a predetermined intensity value targeted for the surface. The controller adjusts the power of the sources as a function of the variation to ensure an optimal distribution of light intensity over the surface.

Abstract: Ultraviolet radiation is directed within an area. Items located within the area and/or one or more conditions of the area are monitored over a period of time. Based on the monitoring, ultraviolet radiation sources are controlled by adjusting a direction, an intensity, a pattern, and/or a spectral power of the ultraviolet radiation generated by the ultraviolet radiation source. Adjustments to the ultraviolet radiation source(s) can correspond to one of a plurality of selectable operating configurations including a storage life preservation operating configuration, a disinfection operating configuration, and an ethylene decomposition operating configuration.

Abstract: A semiconductor layer including a plurality of inhomogeneous regions is provided. Each inhomogeneous region has one or more attributes that differ from a material forming the semiconductor layer. The inhomogeneous regions can include one or more regions configured based on radiation having a target wavelength. These regions can include transparent and/or reflective regions. The inhomogeneous regions also can include one or more regions having a higher conductivity than a conductivity of the radiation-based regions, e.g., at least ten percent higher. In one embodiment, the semiconductor layer is used to form an optoelectronic device.

Abstract: A semiconductor layer including a plurality of inhomogeneous regions is provided. Each inhomogeneous region has one or more attributes that differ from a material forming the semiconductor layer. The inhomogeneous regions can include one or more regions configured based on radiation having a target wavelength. These regions can include transparent and/or reflective regions. The inhomogeneous regions also can include one or more regions having a higher conductivity than a conductivity of the radiation-based regions, e.g., at least ten percent higher. In one embodiment, the semiconductor layer is used to form an optoelectronic device.

Abstract: A method of fabricating a light emitting diode, which includes an n-type contact layer and a light generating structure adjacent to the n-type contact layer, is provided. The light generating structure includes a set of quantum wells. The contact layer and light generating structure can be configured so that a difference between an energy of the n-type contact layer and an electron ground state energy of a quantum well is greater than an energy of a polar optical phonon in a material of the light generating structure. Additionally, the light generating structure can be configured so that its width is comparable to a mean free path for emission of a polar optical phonon by an electron injected into the light generating structure.

Abstract: An optoelectronic device with a multi-layer contact is described. The optoelectronic device can include an n-type semiconductor layer having a surface. A mesa can be located over a first portion of the surface of the n-type semiconductor layer and have a mesa boundary. An n-type contact region can be located over a second portion of the surface of the n-type semiconductor contact layer entirely distinct from the first portion, and be at least partially defined by the mesa boundary. A first n-type metallic contact layer can be located over at least a portion of the n-type contact region in proximity of the mesa boundary, where the first n-type metallic contact layer forms an ohmic contact with the n-type semiconductor layer. A second metallic contact layer can be located over a second portion of the n-type contact region, where the second metallic contact layer is formed of a reflective metallic material.