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.

Abstract: A solution for disinfecting a screen of an item using ultraviolet radiation is provided. The solution can provide an electronic device including a screen utilized by a user of the electronic device. The screen can be an ultraviolet transparent screen that covers at least some of the internal portion of the electronic device and a set of ultraviolet radiation sources can be located adjacent to the transparent screen. The set of ultraviolet radiation sources can be configured to generate ultraviolet radiation directed towards an external surface of the ultraviolet transparent screen. The electronic device can further include a monitoring and control system, which can manage the ultraviolet radiation generation by monitoring a set of attributes relating to the external surface of the screen and controlling, based on the monitoring, ultraviolet radiation directed at the external surface of the screen.

Abstract: A profiled surface for improving the propagation of radiation through an interface is provided. The profiled surface includes a set of large roughness components providing a first variation of the profiled surface having a characteristic scale approximately an order of magnitude larger than a target wavelength of the radiation. The set of large roughness components can include a series of truncated shapes. The profiled surface also includes a set of small roughness components superimposed on the set of large roughness components and providing a second variation of the profiled surface having a characteristic scale on the order of the target wavelength of the radiation.

Abstract: An approach for controlling light exposure of a light sensitive object is described. Aspects of this approach involve using a first set of radiation sources to irradiate the object with visible radiation and infrared radiation. A second set of radiation sources spot irradiate the object in a set of locations with a target ultraviolet radiation having a range of wavelengths. Radiation sensors detect radiation reflected from the object and environment condition sensors detect conditions of the environment in which the object is located during irradiation. A controller controls irradiation of the light sensitive object by the first and second set of radiation sources according to predetermined optimal irradiation settings specified for various environmental conditions. In addition, the controller adjusts irradiation settings of the first and second set of radiation sources as a function of measurements obtained by the various sensors.

Abstract: An opto-electronic device with two-dimensional injection layers is described. The device can include a semiconductor structure with a semiconductor layer having one of an n-type semiconductor layer or a p-type semiconductor layer, and a light generating structure formed on the semiconductor layer. A set of tilted semiconductor heterostructures is formed over the semiconductor structure. Each tilted semiconductor heterostructure includes a core region, a set of shell regions adjoining a sidewall of the core region, and a pair of two-dimensional carrier accumulation (2DCA) layers. Each 2DCA layer is formed at a heterointerface between one of the sidewalls of the core region and one of the shell regions. The sidewalls of the core region, the shell regions, and the 2DCA layers each having a sloping surface, wherein each 2DCA layer forms an angle with a surface of the semiconductor structure.

Abstract: A contact to a semiconductor layer in a light emitting structure is provided. The contact can include a plurality of contact areas formed of a metal and separated by a set of voids. The contact areas can be separated from one another by a characteristic distance selected based on a set of attributes of a semiconductor contact structure of the contact and a characteristic contact length scale of the contact. The voids can be configured to increase an overall reflectivity or transparency of the contact.

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 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 solution for disinfecting flowable products, such as liquids, suspensions, creams, colloids, emulsions, powders, and/or the like, as well as accessories and products relating thereto, such as containers, caps, brushes, applicators, and/or the like, using ultraviolet radiation is provided. In an embodiment, an ultraviolet impermeable cap is configured to enclose a volume corresponding to a flowable product. At least one ultraviolet radiation source can be mounted on the cap and be configured to generate ultraviolet radiation for disinfecting the enclosed area. The ultraviolet radiation source can be configured to only generate ultraviolet radiation when the volume is enclosed by the ultraviolet impermeable cap.

Abstract: A normally-off transistor with a high operating voltage is provided. The transistor can include a barrier above the channel and an additional barrier layer located below the channel. A source electrode and a drain electrode are connected to the channel and a gate electrode is connected to the additional barrier layer located below the channel. The bandgap for each of the barrier layers can be larger than the bandgap for the channel. A polarization charge induced at the interface between the additional barrier layer below the channel and the channel depletes the channel. A voltage can be applied to the bottom barrier to induce free carriers into the channel and turn the channel on.

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: 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 device including a first semiconductor layer and a contact to the first semiconductor layer is disclosed. An interface between the first semiconductor layer and the contact includes a first roughness profile having a characteristic height and a characteristic width. The characteristic height can correspond to an average vertical distance between crests and adjacent valleys in the first roughness profile. The characteristic width can correspond to an average lateral distance between the crests and adjacent valleys in the first roughness profile.

Abstract: A solution for cleaning and/or sterilizing one or more surfaces in a bathroom is provided. The sterilization can be performed using ultraviolet sources, which can emit ultraviolet radiation directed onto the surface(s). The cleaning can be performed using a fluid, such as water, that is flowed over the surface(s). The surface(s) can include at least a seat of a toilet and/or other surfaces associated with the toilet.

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 contact to a semiconductor heterostructure is described. In one embodiment, there is an n-type semiconductor contact layer. A light generating structure formed over the n-type semiconductor contact layer has a set of quantum wells and barriers configured to emit or absorb target radiation. An ultraviolet transparent semiconductor layer having a non-uniform thickness is formed over the light generating structure. A p-type contact semiconductor layer having a non-uniform thickness is formed over the ultraviolet transparent semiconductor layer.

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 solution for disinfecting a fluid, colloid, mixture, and/or the like using ultraviolet radiation is provided. An ultraviolet transparent enclosure can include an inlet and an outlet for a flow of media to be disinfected. The ultraviolet transparent enclosure includes a material that is configured to prevent biofouling within the ultraviolet transparent enclosure. A set of ultraviolet radiation sources are located adjacent to the ultraviolet transparent enclosure and are configured to generate ultraviolet radiation towards the ultraviolet transparent enclosure.

Abstract: A device comprising a semiconductor layer including a plurality of compositional inhomogeneous regions is provided. The difference between an average band gap for the plurality of compositional inhomogeneous regions and an average band gap for a remaining portion of the semiconductor layer can be at least thermal energy. Additionally, a characteristic size of the plurality of compositional inhomogeneous regions can be smaller than an inverse of a dislocation density for the semiconductor layer.

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.