Abstract: In the present invention, a fabrication process for epitaxy onto back-side patterned substrate, where the substrate patterns were defined prior to epitaxy and therefore simplify post growth processing. Specifically, for LED devices, said fabrication process reduces the post growth processing steps required to obtain high LEE due to strong scattering of the back-side features defined on the substrate. The features defined on the back-side patterned substrate scatters strongly with light emitted from the LED devices. Methods of obtaining such features include wet and dry etching.

Abstract: Semiconductor structures involving multiple quantum wells provide increased efficiency of UV and visible light emitting diodes (LEDs) and other emitter devices, particularly at high driving current. LEDs made with the new designs have reduced efficiency droop under high current injection and increased overall external quantum efficiency. The active region of the devices includes separation layers configured between the well layers, the one or more separation regions being configured to have a first mode to act as one or more barrier regions separating a plurality of carriers in a quantum confined mode in each of the quantum wells being provided on each side of the one or more separation layers and a second mode to cause spreading of the plurality of carriers across each of the quantum wells to increase an overlap integral of all of the plurality of carriers. The devices and methods of the invention provide improved efficiency for solid state lighting, including high efficiency ultraviolet LEDs.

Abstract: A device for providing ultraviolet light includes a shell for a portable device, wherein the shell includes an interior region and an exterior region, wherein the interior region is adapted to be disposed adjacent to the portable device, a power source configured to provide electrical power, a and an ultraviolet light source coupled to the power source and embedded into the exterior region of the shell, wherein the ultraviolet light source is configured to output the ultraviolet light in response to the electrical power.

Abstract: Semiconductor structures involving multiple quantum wells provide increased efficiency of UV and visible light emitting diodes (LEDs) and other emitter devices, particularly at high driving current. LEDs made with the new designs have reduced efficiency droop under high current injection and increased overall external quantum efficiency. The active region of the devices includes separation layers configured between the well layers, the one or more separation regions being configured to have a first mode to act as one or more barrier regions separating a plurality of carriers in a quantum confined mode in each of the quantum wells being provided on each side of the one or more separation layers and a second mode to cause spreading of the plurality of carriers across each of the quantum wells to increase an overlap integral of all of the plurality of carriers. The devices and methods of the invention provide improved efficiency for solid state lighting, including high efficiency ultraviolet LEDs.

Abstract: A method of growing an AlGaN semiconductor material utilizes an excess of Ga above the stoichiometric amount typically used. The excess Ga results in the formation of band structure potential fluctuations that improve the efficiency of radiative recombination and increase light generation of optoelectronic devices, in particular ultraviolet light emitting diodes, made using the method. Several improvements in UV LED design and performance are also provided for use together with the excess Ga growth method. Devices made with the method can be used for water purification, surface sterilization, communications, and data storage and retrieval.