Abstract: A conventional semiconductor LED is modified to include a microlenslayer over its light-emitting surface. The LED may have an active layer including at least one quantum well layer of InGaN and GaN. The microlens layer includes a plurality of concave microstructures that cause light rays emanating from the LED to diffuse outwardly, leading to an increase in the light extraction efficiency of the LED. The concave microstructures may be arranged in a substantially uniform array, such as a close-packed hexagonal array. The microlens layer is preferably constructed of curable material, such as polydimethylsiloxane (PDMS), and is formed by soft-lithography imprinting by contacting fluid material of the microlens layer with a template bearing a monolayer of homogeneous microsphere crystals, to cause concave impressions, and then curing the material to fix the concave microstructures in the microlens layer and provide relatively uniform surface roughness.

Abstract: The use of an abbreviated GaN growth mode on nano-patterned AGOG sapphire substrates, which utilizes a process of using 15 nm low temperature GaN buffer and bypassing etch-back and recovery processes during epitaxy, enables the growth of high-quality GaN template on nano-patterned AGOG sapphire. The GaN template grown on nano-patterned AGOG sapphire by employing abbreviated growth mode has two orders of magnitude lower threading dislocation density than that of conventional GaN template grown on planar sapphire. The use of abbreviated growth mode also leads to significant reduction in cost of the epitaxy. The growths and characteristics of InGaN quantum wells (QWs) light emitting diodes (LEDs) on both templates were compared. The InGaN QWs LEDs grown on the nano-patterned AGOG sapphire demonstrated at least a 24% enhancement of output power enhancement over that of LEDs grown on conventional GaN templates.

Abstract: A III-nitride based device provides improved current injection efficiency by reducing thermionic carrier escape at high current density. The device includes a quantum well active layer and a pair of multi-layer barrier layers arranged symmetrically about the active layer. Each multi-layer barrier layer includes an inner layer abutting the active layer; and an outer layer abutting the inner layer. The inner barrier layer has a bandgap greater than that of the outer barrier layer. Both the inner and the outer barrier layer have bandgaps greater than that of the active layer. InGaN may be employed in the active layer, AlInN, AlInGaN or AlGaN may be employed in the inner barrier layer, and GaN may be employed in the outer barrier layer. Preferably, the inner layer is thin relative to the other layers. In one embodiment the inner barrier and active layers are 15 ? and 24 ? thick, respectively.

Abstract: A double-metallic deposition process is used whereby adjacent layers of different metals are deposited on a substrate. The surface plasmon frequency of a base layer of a first metal is tuned by the surface plasmon frequency of a second layer of a second metal formed thereon. The amount of tuning is dependent upon the thickness of the metallic layers, and thus tuning can be achieved by varying the thicknesses of one or both of the metallic layers. In a preferred embodiment directed to enhanced LED technology in the green spectrum regime, a double-metallic Au/Ag layer comprising a base layer of gold (Au) followed by a second layer of silver (Ag) formed thereon is deposited on top of InGaN/GaN quantum wells (QWs) on a sapphire/GaN substrate.

Abstract: A light emitting device comprising a staggered composition quantum well.

Abstract: A gallium nitride-based device has a first GaN layer and a type II quantum well active region over the GaN layer. The type II quantum well active region comprises at least one InGaN layer and at least one GaNAs layer comprising 1.5 to 8% As concentration. The type II quantum well emits in the 400 to 700 nm region with reduced polarization affect.

Abstract: A tight emitting device comprises at least one p-type layer and at least one n-type layer and a microlens array surface. A method for improving light efficiency of a light emitting device, comprises depositing polystyrene microspheres by rapid convection deposition on surface of light emitting device; depositing a monolayer of close-packed SIO2 microspheres onto the polystyrene microspheres; and heal treating to convert the polystyrene microspheres into a planar microlayer film to provide a surface comprising substantially two-dimensional (2D) hexagonal close-packed S1O2 colloidal microsphere crystals partially imposed into a polystyrene monolayer film.

Abstract: A gallium nitride-based device has a first GaN layer and a type II quantum well active region over the GaN layer. The type II quantum well active region comprises at least one InGaN layer and at least one GaNAs layer comprising 1.5 to 8% As concentration. The type II quantum well emits in the 400 to 700 nm region with reduced polarization affect.

Abstract: A gallium nitride-based device has a first GaN layer and a type II quantum well active region over the GaN layer. The type II quantum well active region comprises at least one InGaN layer and at least one GaNAs layer comprising 1.5 to 8% As concentration. The type II quantum well emits in the 400 to 700 nm region with reduced polarization affect.

Abstract: In accordance with the present invention, GaAs-based optoelectronic devices have an active region that includes a well layer composed of a compressively-strained semiconductor that is free, or substantially free, of nitrogen disposed between two barrier layers composed of a nitrogen- and indium-containing semiconductor.

Abstract: A gallium nitride-based device has a first GaN layer and a type II quantum well active region over the GaN layer. The type II quantum well active region comprises at least one InGaN layer and at least one GaNAs layer, wherein the InGaN comprises a graded molar In concentration.

Abstract: A gallium nitride-based device has a first GaN layer and a type II quantum well active region over the GaN layer. The type II quantum well active region comprises at least one InGaN layer and at least one GaNAs layer comprising 1.5 to 8% As concentration. The type II quantum well emits in the 400 to 700 nm region with reduced polarization affect.

Abstract: In accordance with the present invention, GaAs-based optoelectronic devices have an active region that includes a well layer composed of a compressively-strained semiconductor that is free, or substantially free, of nitrogen disposed between two barrier layers composed of a nitrogen- and indium-containing semiconductor.

Abstract: Semiconductor optoelectronic devices such as diode lasers are formed on InP substrates with an active region with an InAsN or InGaAsN electron quantum well layer and a GaAsSb or InGaAsSb hole quantum well layer which form a type II quantum well. The active region may be incorporated in various devices to provide light emission at relatively long wavelengths, including light emitting diodes, amplifiers, surface emitting lasers and edge-emitting lasers.

Abstract: Semiconductor optoelectronic devices such as diode lasers are formed on InP substrates with an active region with an InAsN or InGaAsN electron quantum well layer and a GaAsSb or InGaAsSb hole quantum well layer which form a type II quantum well. The active region may be incorporated in various devices to provide light emission at relatively long wavelengths, including light emitting diodes, amplifiers, surface emitting lasers and edge-emitting lasers.

Abstract: As edge-emitting semiconductor laser incorporating a narrow waveguide design is disclosed. The narrow waveguide expands the lateral mode size, creates a large modal spot size, and insures higher-order modes are beyond cutoff. Separate current confinement allows the current injection region to match the mode size. The resulting device exhibits single-mode operation with a large spot-size to high output powers.

Abstract: Semiconductor optoelectronic devices such as diode lasers are formed on GaAs with an active region with a GaAsN electron quantum well layer and a GaAsSb hole quantum well layer which form a type II quantum well. The active region may be incorporated in various devices to provide light emission at relatively long wavelengths, including light emitting diodes, amplifiers, surface emitting lasers and edge-emitting lasers.

Abstract: An edge-emitting semiconductor laser incorporating a narrow waveguide design is disclosed. The narrow waveguide expands the lateral mode size, creates a large modal spot size, and insures higher-order modes are beyond cutoff. Separate current confinement allows the current injection region to match the mode size. The resulting device exhibits single-mode operation with a large spot-size to high output powers.

Abstract: Semiconductor optoelectronic devices such as diode lasers are formed on GaAs with an active region with a GaAsN electron quantum well layer and a GaAsSb hole quantum well layer which form a type II quantum well. The active region may be incorporated in various devices to provide light emission at relatively long wavelengths, including light emitting diodes, amplifiers, surface emitting lasers and edge-emitting lasers.