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 illuminating plants is provided. An illustrative system can include: a set of visible light sources configured to emit visible radiation directed at the plant; a set of ultraviolet radiation sources configured to emit ultraviolet radiation directed at the plant; and a set of sensors, wherein at least one sensor is configured to detect a fluorescence emitted from the plant due to the ultraviolet radiation and a fluorescence emitted from the plant due to the visible radiation.

Abstract: A heterostructure, such as a group III nitride heterostructure, for use in an optoelectronic device is described. The heterostructure can include 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: 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: 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: A semiconductor heterostructure for an optoelectronic device is disclosed. The semiconductor heterostructure includes at least one stress control layer within a plurality of semiconductor layers used in the optoelectronic device. Each stress control layer includes stress control regions separated from adjacent stress control regions by a predetermined spacing. The stress control layer induces one of a tensile stress and a compressive stress in an adjacent semiconductor layer.

Abstract: An approach for curing ultraviolet sensitive polymer materials (e.g., polymer inks, coatings, and adhesives) using ultraviolet radiation is disclosed. The ultraviolet sensitive polymer materials curing can utilize ultraviolet light at different wavelength emissions arranged in a random, mixed or sequential arrangement. In one embodiment, an ultraviolet light C (UV-C) radiation emitter having a set of UV-C sources that emit UV-C radiation at a predetermined UV-C duration and intensity operate in conjunction with an ultraviolet light B (UV-B) radiation emitter having a set of UV-B sources configured to emit UV-B radiation at a predetermined UV-B duration and intensity and/or an ultraviolet light A (UV-A) radiation emitter having a set of UV-A sources configured to emit UV-A radiation at a predetermined UV-A duration and intensity, to cure the ultraviolet sensitive polymer materials.

Abstract: An improved heterostructure for an optoelectronic device is provided. The heterostructure includes an active region, an electron blocking layer, and a p-type contact layer. The heterostructure can include a p-type interlayer located between the electron blocking layer and the p-type contact layer. In an embodiment, the electron blocking layer can have a region of graded transition. The p-type interlayer can also include a region of graded transition.

Abstract: An optoelectronic device configured for improved light extraction through a region of the device other than the substrate is described. A group III nitride semiconductor layer of a first polarity is located on the substrate and an active region can be located on the group III nitride semiconductor layer. A group III nitride semiconductor layer of a second polarity, different from the first polarity, can located adjacent to the active region. A first contact can directly contact the group III nitride semiconductor layer of the first polarity and a second contact can directly contact the group III nitride semiconductor layer of the second polarity. Each of the first and second contacts can include a plurality of openings extending entirely there through and the first and second contacts can form a photonic crystal structure. Some or all of the group III nitride semiconductor layers can be located in nanostructures.

Abstract: An improved heterostructure for an optoelectronic device is provided. The heterostructure includes an active region, an electron blocking layer, and a p-type contact layer. The electron blocking layer is located between the active region and the p-type contact layer. In an embodiment, the electron blocking layer can include a plurality of sublayers that vary in composition.

Abstract: An improved heterostructure for an optoelectronic device is provided. The heterostructure includes an active region, an electron blocking layer, and a p-type contact layer. The p-type contact layer and electron blocking layer can be doped with a p-type dopant. The dopant concentration for the electron blocking layer can be at most ten percent the dopant concentration of the p-type contact layer. A method of designing such a heterostructure is also described.

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 growth layer having a growth surface with protruding domains is described. The protruding domains can be separated by a substantially flat growth surface located between the protruding domains. A protruding domain can include an internal region that can be filled with a gas and/or can be partially or completely filled with one or more materials that differ from the material of the growth layer, which forms an outer surface of each of the protruding domains.

Abstract: Ultraviolet illumination with optical elements to irradiate objects and/or fluid for purposes of sterilization, disinfection, and/or cleaning. The objects and/or fluid can be irradiated using an ultraviolet illuminator having at least one ultraviolet light emitting source. An ultraviolet transparent housing encapsulates the at least one ultraviolet light emitting source. The ultraviolet transparent housing includes an ultraviolet transparent material that emits ultraviolet light from the at least one ultraviolet light emitting source while preventing humidity from penetrating the ultraviolet transparent housing and damaging the at least one ultraviolet light emitting source. At least one ultraviolet transparent optical element is located about the ultraviolet transparent housing interspersed with the ultraviolet transparent material.

Abstract: Ultraviolet irradiation of food handling instruments for purposes of sterilization, disinfection, cleaning and other treatment capabilities. A housing having receptacles receives one or more food handling instruments. Ultraviolet light emitting sources located about the receptacles can direct ultraviolet light towards the receptacles and any food handling instruments placed therein. One or more sensors located about the receptacles can detect operational conditions associated with the receptacles and any food handling instruments received therein. A control unit, operatively coupled to the ultraviolet light emitting sources and the one or more sensors, manages the irradiation of the receptacles and any food handling instruments in the receptacles as a function of the operational conditions detected by the one or more sensors.

Abstract: An approach for treating a fluid transport conduit with ultraviolet radiation is disclosed. A light guiding unit, operatively coupled to a set of ultraviolet radiation sources, encloses the fluid transport conduit. The light guiding unit directs ultraviolet radiation emitted from the ultraviolet radiation sources to ultraviolet transparent sections on an outer surface of the fluid transport conduit. The emitted ultraviolet radiation passes through the ultraviolet transparent sections, penetrates the fluid transport conduit and irradiates the internal walls. A control unit adjusts a set of operating parameters of the ultraviolet radiation sources as a function of the removal of contaminants from the internal walls of the fluid transport conduit.

Abstract: An approach for preparing a vaccine using ultraviolet radiation is described. Aspects of this approach involve multiple iterations of inactivation of the vaccine using an ultraviolet radiation source at a set of different wavelengths and dosages. A recognition test of the vaccine using the set of different wavelengths and dosages is performed after the multiple iterations of inactivation. A controller compares results from the inactivation test and the recognition test to determine an area of acceptable radiation dosages and wavelengths generated from the ultraviolet radiation source that irradiate the live organisms without affecting efficacy and safety of the vaccine. The area of acceptable ultraviolet radiation dosages and wavelengths is representative of a difference between an ultraviolet radiation dosage that is required for inactivation and an ultraviolet radiation dosage that leads to a loss of recognition.

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: 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.

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.