Abstract: An approach for providing illumination with a blue UV light source, which can be used in combination with a visible light source is disclosed. In operation, the visible light source emits visible light at a first intensity. The blue UV light source emits blue UV light at a second intensity. The blue UV light stimulates fluorescence from a surface of an object illuminated by the blue UV light. A sensor can detect the intensity of the fluorescence from the surface illuminated by the blue UV light source. A control module can be operatively coupled to the visible light source, the blue UV light source, and the at least one sensor, and be configured to change the intensity of the visible light and/or the intensity of the blue UV light as a function of the fluorescent intensity detected by the sensor.

Abstract: A solution for treating a fluid, such as water, is provided. An ultraviolet transparency of a fluid can be determined before or as the fluid enters a disinfection chamber. In the disinfection chamber, the fluid can be irradiated by ultraviolet radiation to harm microorganisms that may be present in the fluid. One or more attributes of the disinfection chamber, fluid flow, and/or ultraviolet radiation can be adjusted based on the transparency to provide more efficient irradiation and/or higher disinfection rates. In addition, various attributes of the disinfection chamber, such as the position of the inlet(s) and outlet(s), the shape of the disinfection chamber, and other attributes of the disinfection chamber can be utilized to create a turbulent flow of the fluid within the disinfection chamber to promote mixing and improve uniform ultraviolet exposure.

Abstract: Fabrication of a heterostructure, such as a group III nitride heterostructure, for use in an optoelectronic device is described. The heterostructure can be epitaxially grown on a sacrificial layer, which is located on a substrate structure. The sacrificial layer can be at least partially decomposed using a laser. The substrate structure can be completely removed from the heterostructure or remain attached thereto. One or more additional solutions for detaching the substrate structure from the heterostructure can be utilized. The heterostructure can undergo additional processing to form the optoelectronic device.

Abstract: A system for providing ultraviolet treatment of volatile organic compounds (VOCs) is disclosed. The system can include a first gas conduit to carry a stream of gas having VOCs and a second gas conduit to carry a second stream of gas containing a partial pressure of water vapor. A gas treatment unit can be coupled to the first gas conduit and the second gas conduit. The gas treatment unit can form hydroxyl radicals from the water vapor in the stream of gas carried by the second gas conduit and inject the radicals in the first gas conduit to decrease the presence of the VOCs. The gas treatment unit can include a photocatalyst component and at least one ultraviolet radiation source to irradiate the photocatalyst component with ultraviolet radiation. To this extent, the irradiated photocatalyst component disassociates the gas containing the water vapor to form the hydroxyl radicals.

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, which has a shape including a plurality of interconnected fingers. The n-type semiconductor layer can have a shape at least partially defined by the mesa boundary. A first n-type contact layer can be located adjacent to another portion of the n-type semiconductor contact layer, where the first n-type contact layer forms an ohmic contact with the n-type semiconductor layer. A second contact layer can be located over a second portion of the n-type semiconductor contact layer, where the second contact layer is formed of a reflective material.

Abstract: Ultraviolet radiation is directed within an area. The storage area is scanned and monitored for the presence of biological activity within designated zones. Once biological activity is identified, ultraviolet radiation is directed to sterilize and disinfect designated zones within the storage area.

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 solution for controlling mildew in a cultivated area is described. The solution can include a set of ultraviolet sources that are configured to emit ultraviolet radiation in an ultraviolet range of approximately 260 nanometers to approximately 310 nanometers to harm mildew present on a plant or ground surface. A set of sensors can be utilized to acquire plant data for at least one plant surface of a plant, which can be processed to determine a presence of mildew on the at least one plant surface. Additional features can be included to further affect the growth environment for the plant. A feedback process can be implemented to improve one or more aspects of the growth environment.

Abstract: Semiconductor structures formed with annealing for use in the fabrication of optoelectronic devices. The semiconductor structures can include a substrate, a nucleation layer and a buffer layer. The nucleation layer and the buffer layer can be epitaxially grown and then annealed. The temperature of the annealing of the nucleation layer and the buffer layer is greater than the temperature of the epitaxial growth of the layers. The annealing reduces the dislocation density in any subsequent layers that are added to the semiconductor structures. A desorption minimizing layer epitaxially grown on the buffer layer can be used to minimize desorption during the annealing of the layer which also aids in curtailing dislocation density and cracks in the semiconductor structures.

Abstract: A method of fabricating a device using 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. A device including one or more of these features also is provided.

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: An emitting structure for simulating an irradiance signature of a missile is provided. The emitting structure includes one or more radiation sources, each of which includes at least one ultraviolet radiation source and at least one infrared radiation source. The emitting structure also includes a spherical shell and a mechanism for positioning the radiation source(s) along a three dimensional boundary of the spherical shell. The emitting structure can locate and operate one of the radiation sources to simulate the irradiance signature of the missile.

Abstract: Ultraviolet radiation is directed within an area. The storage area is scanned and monitored for the presence of biological activity within designated zones. Once biological activity is identified, ultraviolet radiation is directed to sterilize and disinfect designated zones within the storage area.

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: Heterostructures for use in optoelectronic devices are described. One or more parameters of the heterostructure can be configured to improve the reliability of the corresponding optoelectronic device. The materials used to create the active structure of the device can be considered in configuring various parameters the n-type and/or p-type sides of the heterostructure.

Abstract: An interface including roughness components for improving the propagation of radiation through the interface is provided. The interface includes a first profiled surface of a first layer comprising a set of large roughness components providing a first variation of the first profiled surface having a first characteristic scale and a second profiled surface of a second layer comprising a set of small roughness components providing a second variation of the second profiled surface having a second characteristic scale. The first characteristic scale is approximately an order of magnitude larger than the second characteristic scale. The surfaces can be bonded together using a bonding material, and a filler material also can be present in the interface.

Abstract: Ultraviolet radiation is directed within an area. The target wavelength ranges and/or target intensity ranges of the ultraviolet radiation sources can correspond to at least one of a plurality of selectable operating configurations including a sterilization operating configuration and a preservation operating configuration.

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 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 composite material, which can be used as an encapsulant for an ultraviolet device, is provided. The composite material includes a matrix material and at least one filler material incorporated in the matrix material that are both at least partially transparent to ultraviolet radiation of a target wavelength. The filler material includes microparticles and/or nanoparticles and can have a thermal coefficient of expansion significantly smaller than a thermal coefficient of expansion of the matrix material for relevant atmospheric conditions. The relevant atmospheric conditions can include a temperature and a pressure present during each of: a curing and a cool down process for fabrication of a device package including the composite material and normal operation of the ultraviolet device within the device package.