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: Ultraviolet radiation is directed within a storage area at target wavelengths, target intensities, a target temporal distribution, and/or a target spatial distribution. A set of ultraviolet radiation sources generate ultraviolet radiation directed at a set of items located within the storage area. A first ultraviolet radiation source operates at a first peak wavelength and a second ultraviolet radiation source operates at a second peak wavelength that is different from the first peak wavelength.

Abstract: A semiconductor heterostructure for an optoelectronic device with improved light emission is disclosed. The heterostructure can include a first semiconductor layer having a first index of refraction n1. A second semiconductor layer can be located over the first semiconductor layer. The second semiconductor layer can include a laminate of semiconductor sublayers having an effective index of refraction n2. A third semiconductor layer having a third index of refraction n3 can be located over the second semiconductor layer. The first index of refraction n1 is greater than the second index of refraction n2, which is greater than the third index of refraction n3.

Abstract: A wearable fluorescent article of adornment with ultraviolet radiation source of excitation is described. At least one ultraviolet light emitting source can irradiate a fluorescent material with ultraviolet radiation. The fluorescent material can generate fluorescent light in response to excitation of the fluorescent material with ultraviolet radiation emitted from the at least one ultraviolet light emitting source. The article of adornment can transmit the fluorescent light generated from the fluorescent material while absorbing the ultraviolet radiation. A control unit can control irradiation of the fluorescent material with the at least one ultraviolet light emitting source, while a power supply component can power the at least one ultraviolet light emitting source and/or the control unit.

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 and/or blue-ultraviolet radiation 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 irradiation of fluids for the purposes of disinfection, sterilization and modification of a target organic compound found within the fluids. The target compound in the fluids can have an absorption spectra with an ultraviolet wavelength ranging from 230 nm to 360 nm. The absorption spectra includes a first and second set of wavelengths corresponding to absorption peaks and absorption valleys in the absorption spectra, respectively. A-set of ultraviolet radiation sources irradiate the fluids. The set of ultraviolet radiation sources operate at a set of peak wavelengths ranging from 230 nm to 360 nm with a peak full width at half maximum that is less than 20 nm. The set of peak wavelengths are proximate to at least one wavelength in the second set of wavelengths corresponding to the absorption valleys in the absorption spectra with a variation of a full width half maximum of the absorption valley.

Abstract: Ultraviolet irradiation of an aquatic environment for the purposes of sterilization, disinfection, and/or cleaning fluids and surfaces associated with the aquatic environment. The aquatic environment can be irradiated using an ultraviolet illuminator having at least one ultraviolet radiation source and at least one sensor to detect conditions of the aquatic environment including fluid conditions and/or surface conditions associated with the aquatic environment. A control unit, operatively coupled to the at least one ultraviolet radiation source and the at least one sensor, determines a presence of algae growth about the aquatic environment. The control unit is further configured to direct the at least one ultraviolet radiation source to irradiate the aquatic environment at locations where there is a presence of algae growth for removal and suppression of further growth, monitor the irradiation with the at least one sensor, and adjust irradiation parameters as a function of detected conditions.

Abstract: A solution for generating ultraviolet diffusive radiation is provided. A diffusive ultraviolet radiation illuminator includes at least one ultraviolet radiation source located within a reflective cavity that includes a plurality of surfaces. At least one of the plurality of surfaces can be configured to diffusively reflect at least 70% of the ultraviolet radiation and at least one of the plurality of surfaces can be configured to transmit at least 30% of the ultraviolet radiation and reflect at least 10% of the ultraviolet radiation.

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 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 solid-state light source (SSLS) with an integrated electronic modulator is described. A device can include a SSLS having an active p-n junction region is formed within the SSLS for electron-hole pair recombination and light emission. the active p-n junction region can include a n-type semiconductor layer, a p-type semiconductor layer and a light generating structure formed there between. A pair of current supply electrodes can be formed to receive a drive current from a current supply source that drives the SSLS. A field-effect transistor (FET) modulator can be monolithically integrated with the SSLS for modulation thereof. The FET modulator can receive a modulation voltage from a modulation voltage source. The modulation voltage includes voltage pulses having a pulse amplitude and polarity to turn on and off current flowing through the FET modulator. These voltage pulses enable the FET modulator to control the drive current supplied to the SSLS.

Abstract: A perforating ohmic contact to a semiconductor layer in a semiconductor structure is provided. The perforating ohmic contact can include a set of perforating elements, which can include a set of metal protrusions laterally penetrating the semiconductor layer(s). The perforating elements can be separated from one another by a characteristic length scale selected based on a sheet resistance of the semiconductor layer and a contact resistance per unit length of a metal of the perforating ohmic contact contacting the semiconductor layer. The structure can be annealed using a set of conditions configured to ensure formation of the set of metal protrusions.

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: A diffusive layer including a laminate of a plurality of transparent films is provided. At least one of the plurality of transparent films includes a plurality of diffusive elements with a concentration that is less than a percolation threshold. The plurality of diffusive elements are optical elements that diffuse light that is impinging on such element. The plurality of diffusive elements can be diffusively reflective, diffusively transmitting or combination of both. The plurality of diffusive elements can include fibers, grains, domains, and/or the like. The at least one film can also include a powder material for improving the diffusive emission of radiation and a plurality of particles that are fluorescent when exposed to radiation.

Abstract: A solution for fabricating a semiconductor structure is provided. The semiconductor structure includes a plurality of semiconductor layers grown over a substrate using a set of epitaxial growth periods. During each epitaxial growth period, a first semiconductor layer having one of: a tensile stress or a compressive stress is grown followed by growth of a second semiconductor layer having the other of: the tensile stress or the compressive stress directly on the first semiconductor layer. One or more of a set of growth conditions, a thickness of one or both of the layers, and/or a lattice mismatch between the layers can be configured to create a target level of compressive and/or shear stress within a minimum percentage of the interface between the layers.

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 can include 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 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 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 heterostructure for use in fabricating an optoelectronic device is provided. The heterostructure includes a layer, such as an n-type contact or cladding layer, that includes thin sub-layers inserted therein. The thin sub-layers can be spaced throughout the layer and separated by intervening sub-layers fabricated of the material for the layer. The thin sub-layers can have a distinct composition from the intervening sub-layers, which alters stresses present during growth of the heterostructure.

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.