Patent application number | Description | Published |
20090090932 | NITRIDE SEMICONDUCTOR ULTRAVIOLET LEDS WITH TUNNEL JUNCTIONS AND REFLECTIVE CONTACT - A structure and method for improving UV LED efficiency is described. The structure utilizes a tunnel junction to separate a P-doped layer of the LED from a n-doped contact layer. The n-doped contact layer allows the use of a highly reflective, low work function metal, such as aluminum, for the p-side contact. The reflectivity at the contact can be further improved by including a phase matching layer in some areas between the contact metal (The metal above the phase matching layer does not necessarily need to have a low work function because it does need to form an ohmic contact with the n-contact layer) and the n-doped contact layer. | 04-09-2009 |
20090152529 | LIGHT EMITTING DEVICES WITH INHOMOGENEOUS QUANTUM WELL ACTIVE REGIONS - A method of fabricating a light emitting device includes modulating a crystal growth parameter to grow a quantum well layer that is inhomogeneous and that has a non-random composition fluctuation across the quantum well layer. | 06-18-2009 |
20090154516 | PARTICLE DISPLAY WITH JET-PRINTED COLOR FILTERS AND SURFACE COATINGS - A method of forming a buried aperture in a nitride light emitting device is described. The method involves forming an aperture layer, typically an amorphous or polycrystalline material over an active layer that includes a nitride material. The aperture layer material typically also includes nitride. The aperture layer is etched to create an aperture which is then filled with a conducting material by epitaxial regrowth. The amorphous layer is crystallized forming an electrically resistive material during or before regrowth. The conducting aperture in the electrically resistive material is well suited for directing current into a light emitting region of the active layer. | 06-18-2009 |
20090283746 | LIGHT-EMITTING DEVICES WITH MODULATION DOPED ACTIVE LAYERS - A semiconductor light emitting device has an n-type layer, a p-type layer, and a light-emitting active layer arranged between the p-type layer and the n-type layer, the active layer having alternating regions of doped and undoped materials. A double heterojunction light emitting device has a bulk active layer having doped portions alternating with undoped portions. A method of manufacturing a light emitting device includes forming a first layer arranged on a substrate, growing an active layer, selectively adding impurities at predetermined times during the growing of the active layer, and forming a second layer arranged on the active layer. | 11-19-2009 |
20100006023 | Method For Preparing Films And Devices Under High Nitrogen Chemical Potential - Nitride semiconductor films, such as for use in solid state light emitting devices and electronic devices, are fabricated in an environment of relatively high nitrogen potential such that nitrogen vacancies in the growing film are reduced. A reactor design, and method for its use, provide high nitrogen precursor partial pressure, precracking of the precursor using a catalytic metal surface, prepyrolyzing the precursor, using catalytically-cracked molecular nitrogen as a nitrogen precursor, and/or exposing the surface to an ambient which is extremely rich in active nitrogen species. Improved efficiency for light emitting devices, particularly in the blue and green wavelengths and improve transport properties in nitride electronic devices, i.e., improved performance from nitride-based devices such as InGaAlN laser diodes, transistors, and light emitting diodes is thereby provided. | 01-14-2010 |
20100063753 | INTEGRATED VAPOR DELIVERY SYSTEMS FOR CHEMICAL VAPOR DEPOSITION PRECURSORS - One disclosed feature of the embodiments is a control processor in a vapor delivery system for chemical vapor deposition precursors. A pressurization rate processor calculates first and second pressurization rate curves at first and second time instants. A volume calculator computes consumed volume based on first and second volumes at the respective first and second time instants. The first and second volumes are computed using slopes of lines fitting the first and second pressurization rate curves. | 03-11-2010 |
20100074292 | Semiconductor Light Emitting Devices With Non-Epitaxial Upper Cladding - The AlGaN upper cladding layer of a nitride laser diode is replaced by a non-epitaxial layer, such as metallic silver. If chosen to have a relatively low refractive index value, the mode loss from absorption in the non-epitaxial cladding layer is acceptably small. If also chosen to have a relatively high work-function, the non-epitaxial layer forms an electrical contact to the nitride semiconductors. An indium-tin-oxide layer may also be employed with the non-epitaxial cladding layer. | 03-25-2010 |
20100127236 | Laser Diode With High Indium Active Layer And Lattice Matched Cladding Layer - A semiconductor laser diode with a high indium content is provided with a lattice matched cladding layer or layers. One or both of the cladding layers may comprise bulk aluminum gallium indium nitride in the ratio of Al | 05-27-2010 |
20100148146 | MONOLITHIC WHITE AND FULL-COLOR LIGHT EMITTING DIODES USING OPTICALLY PUMPED MULTIPLE QUANTUM WELLS - An embodiment is a method and apparatus for a white or full-color light-emitting diode. First single or multiple quantum wells (QWs) at a first wavelength are formed at an active region between a p-type layer and an n-type layer of a light-emitting diode. Multiple passive quantum wells (QWs) are formed within the p-type layer or the n-type layer. The multiple passive QWs are optically pumped by the first or single multiple QWs to generate a desired color. | 06-17-2010 |
20100148147 | MONOLITHIC WHITE AND FULL-COLOR LIGHT EMITTING DIODES USING SELECTIVE AREA GROWTH - An embodiment is a method and apparatus for a white or full-color light-emitting diode. A first mask having a first pattern is applied over surface of an n-type layer. A first active region is grown selectively and including single or multiple quantum wells (QWs) of a first active color to cause a first wavelength shift in a first vicinity area around the first pattern. The first wavelength shift results in an emission of a first desired color according to the first pattern. | 06-17-2010 |
20100148188 | LASER-INDUCED FLAW FORMATION IN NITRIDE SEMICONDUCTORS - An embodiment is a method and apparatus to induce flaw formation in nitride semiconductors. Regions of a thin film structure are selectively decomposed within a thin film layer at an interface with a substrate to form flaws in a pre-determined pattern within the thin film structure. The flaws locally concentrate stress in the pre-determined pattern during a stress-inducing operation. The stress-inducing operation is performed. The stress-inducing operation causes the thin film layer to fracture at the pre-determined pattern. | 06-17-2010 |
20100148197 | SELECTIVE DECOMPOSITION OF NITRIDE SEMICONDUCTORS TO ENHANCE LED LIGHT EXTRACTION - A method of texturing a surface within or immediately adjacent to a template layer of a LED is described. The method uses a texturing laser directed through a substrate to decompose and pit a semiconductor material at the surface to be textured. By texturing the surface, light trapping within the template layer is reduced. Furthermore, by patterning the arrangement of pits, metal coating each pit can be arranged to spread current through the template layer and thus through the n-doped region of a LED. | 06-17-2010 |
20100151602 | LASER ROUGHENING TO IMPROVE LED EMISSIONS - An improved method of forming a LED with a roughened surface is described. Traditional methods of roughening a LED surface utilizes strong etchants that require sealing or protecting exposed areas of the LED. The described method uses a focused laser to separate the LED from the substrate, and a second laser to roughen the LED surface thereby avoiding the use of strong etchants. A mild etchant may be used on the laser roughened LED surface to remove unwanted metals. | 06-17-2010 |
20100166032 | Buried Aperture Nitride Light-Emiting Device - A buried aperture in a nitride light emitting device is described. The aperture is formed in an aperture layer, typically an amorphous or polycrystalline material over an active layer that includes a nitride material. The aperture layer material typically also includes nitride. The aperture layer is etched to create an aperture which is filled with a conducting material by epitaxial regrowth. The amorphous layer is crystallized forming an electrically resistive material during or before regrowth. The conducting aperture in the electrically resistive material is well suited for directing current into a light emitting region of the active layer. | 07-01-2010 |
20100187695 | OUT-OF-PLANE SPRING STRUCTURES ON A SUBSTRATE - A structure has at least one structure component formed of a first material residing on a substrate, such that the structure is out of a plane of the substrate. A first coating of a second material then coats the structure. A second coating of a non-oxidizing material coats the structure at a thickness less than a thickness of the second material. | 07-29-2010 |
20100197062 | LIGHT EMITTING DEVICES WITH INHOMOGENEOUS QUANTUM WELL ACTIVE REGIONS - A method of fabricating a light emitting device includes modulating a crystal growth parameter to grow a quantum well layer that is inhomogeneous and that has a non-random composition fluctuation across the quantum well layer. | 08-05-2010 |
20100295164 | AIRGAP MICRO-SPRING INTERCONNECT WITH BONDED UNDERFILL SEAL - A package includes a pad chip having contact pads, a spring chip having micro-springs in contact with the contact pads to form interconnects, the area in which the micro-springs contact the contact pads forming an interconnect area, an assembly material between the pad chip and the spring chip arranged to form a gap between the pad chip and the spring chip, and an underfill material in a portion of the gap to form a mold from the pad chip and the spring chip. A package includes a pad chip having contact pads, a spring chip having micro-springs in contact with the contact pads to form interconnects, the area in which the micro-springs contact the contact pads forming an interconnect area, an assembly material between the pad chip and the spring chip arranged to form a gap between the pad chip and the spring chip, an underfill material in the gap to form a mold from the pad chip and the spring chip, and at least one wall between the underfill material and the interconnect area. A method of assembling a package includes aligning a pad chip with a spring chip to form at least one interconnect in an interconnect area, adhering the pad chip to the spring chip so that there is a gap between the pad chip and the spring chip, dispensing underfill material into the gap to seal the interconnect area from an environment external to the package, and curing the underfill material to form a solid mold. | 11-25-2010 |
20100295165 | STRESS-ENGINEERED INTERCONNECT PACKAGES WITH ACTIVATOR-ASSISTED MOLDS - A package has a pad chip having contact pads, a spring chip having micro-springs in contact with the contact pads to form interconnects, the area in which the micro-springs contact the contact pads forming an interconnect area, a chemical activator in the interconnect area, and an adhesive responsive to the chemical activator in the interconnect area. A package has a pad chip having contact pads, a spring chip having micro-springs in contact with the contact pads to form interconnects, a chemical activator on one of either the pad chip or the spring chip, and an adhesive responsive to the chemical activator on the other of either the pad chip or the spring chip. A method includes providing a pad chip having contact pads, providing a spring chip having micro-springs, applying a chemical activator to one of either the pad chip or the spring chip, applying an adhesive responsive to the chemical activator on the other of the pad chip or the spring chip, aligning the pad chip to the spring chip such that the micro-springs will contact the contact pads, and pressing the pad chip and the spring chip together such that the chemical activator at least partially cures the adhesive. | 11-25-2010 |
20110039360 | Selective Decomposition Of Nitride Semiconductors To Enhance LED Light Extraction - A method of texturing a surface within or immediately adjacent to a template layer of a LED is described. The method uses a texturing laser directed through a substrate to decompose and pit a semiconductor material at the surface to be textured. By texturing the surface, light trapping within the template layer is reduced. Furthermore, by patterning the arrangement of pits, metal coating each pit can be arranged to spread current through the template layer and thus through the n-doped region of a LED. | 02-17-2011 |
20110051768 | Semiconductor Light Emitting Devices With Non-Epitaxial Upper Cladding - The AlGaN upper cladding layer of a nitride laser diode is replaced by a non-epitaxial layer, such as metallic silver. If chosen to have a relatively low refractive index value, the mode loss from absorption in the non-epitaxial cladding layer is acceptably small. If also chosen to have a relatively high work-function, the non-epitaxial layer forms an electrical contact to the nitride semiconductors. An indium-tin-oxide layer may also be employed with the non-epitaxial cladding layer. | 03-03-2011 |
20110069729 | Vertical Surface Emitting Semiconductor Device - A semiconductor light emitting device includes a pump light source, a gain structure, and an out-coupling mirror. The gain structure is comprised of InGaN layers that have resonant excitation absorption at the pump wavelength. Light from the pump light source causes the gain structure to emit light, which is reflected by the out-coupling mirror back to the gain structure. A distributed Bragg reflector causes internal reflection within the gain structure. The out-coupling mirror permits light having sufficient energy to pass therethrough for use external to the device. A frequency doubling structure may be disposed between the gain structure and the out-coupling mirror. Output wavelengths in the deep-UV spectrum may be achieved. | 03-24-2011 |
20110069730 | Semiconductor Laser with Integrated Contact and Waveguide - A semiconductor light-emitting device has, in place of a traditional separate cladding layer and contact structure, a non-epitaxial contact and waveguide layer. The non-epitaxial contact and waveguide layer is formed of a conductive material and such that it has a recess therein and over the injection region. Air filling the region together with appropriate choice of material for the non-epitaxial contact and waveguide layer creates desired lateral waveguiding. Metallic silver in one choice for this material. The recess may also be filled with a low-loss material having a refractive index higher than that of the material forming the non-epitaxial contact and waveguide layer. Transparent conductive oxides (e.g., indium tin oxide (ITO), zinc oxide (ZnO), etc.), appropriate metal (e.g., gold), or a composite comprising a conductive oxide and a metal, provide low absorption in the UV and near-IR wavelengths of interest, and are thus good candidate materials for within the recess. | 03-24-2011 |
20110150017 | Relaxed InGaN/AlGaN Templates - A relaxed InGaN template employs a GaN or InGaN nucleation layer grown at low temperatures on a conventional base layer (e.g., sapphire). The nucleation layer is typically very rough and multi-crystalline. A single-crystal InGaN buffer layer is then grown at normal temperatures. Although not necessary, the buffer layer is typically undoped, and is usually grown at high pressures to encourage planarization and to improve surface smoothness. A subsequent n-doped cap layer can then be grown at low pressures to form the n-contact of a photonic or electronic device. In some cases, a wetting layer—typically low temperature AlN—is grown prior to the nucleation layer. Other templates, such as AlGaN on Si or SiC, are also produced using the method of the present invention. | 06-23-2011 |
20110268143 | Vertical Surface Emitting Semiconductor Device - A semiconductor light emitting device includes a pump light source, a gain structure, and an out-coupling mirror. The gain structure is comprised of InGaN layers that have resonant excitation absorption at the pump wavelength. Light from the pump light source causes the gain structure to emit light, which is reflected by the out-coupling mirror back to the gain structure. A distributed Bragg reflector causes internal reflection within the gain structure. The out-coupling mirror permits light having sufficient energy to pass therethrough for use external to the device. A frequency doubling structure may be disposed between the gain structure and the out-coupling mirror. Output wavelengths in the deep-UV spectrum may be achieved. | 11-03-2011 |
20110271857 | PRINTING SYSTEM EMPLOYING DEFORMABLE POLYMER PRINTING PLATES - A printing plate has a substrate, an array of cells on the substrate, wherein each cell corresponds to an element of a print image, a deformable polymer material localized into the cells such that each cell is at least partially formed from the deformable polymer material, a reservoir corresponding to each cell to collect the deformable polymer material as needed when the deformable polymer material is one of either melted or softened, and a heater to cause the deformable polymer material to either melt or soften. A method of forming a printing plate provides an array of cells, first heats the array of cells such that the deformable polymer material does one of either melts or softens, actuates the cells in the array to assume a deformed state, cools the array of cells to solidify the cells in the deformed state, second heats the cells such that the deformable polymer material in selected ones of the cells does one of either soften or melt and return to a less deformed state to form a printing pattern, and cools the surface to solidify the deformable polymer material in the printing pattern. A method of forming a printing plate provides an array of cells, heats the array of cells such that the deformable polymer material softens, actuates selected ones of the cells to deform surfaces of the selected ones to form a printing pattern, and cools the array of cells to solidify the printing pattern into a printing plate. | 11-10-2011 |
20110281424 | Relaxed InGaN/AlGaN Templates - A relaxed InGaN template is formed by growing a GaN or InGaN nucleation layer at low temperatures on a conventional base layer (e.g., sapphire). The nucleation layer is typically very rough and multi-crystalline. A single-crystal InGaN buffer layer is then grown at normal temperatures on the nucleation layer. Although not necessary, the buffer layer is typically undoped, and is usually grown at high pressures to encourage planarization and to improve surface smoothness. A subsequent n-doped cap layer can then be grown at low pressures to form the n-contact of a photonic or electronic device. In some cases, a wetting layer—typically low temperature AlN—is grown prior to the nucleation layer. Other templates, such as AlGaN on Si or SiC, are also produced using the method of the present invention. | 11-17-2011 |
20110291074 | Semi-Polar Nitride-Based Light Emitting Structure and Method of Forming Same - A structure and method for producing same provides a solid-state light emitting device with suppressed lattice defects in epitaxially formed nitride layers over a non-c-plane oriented (e.g., semi-polar) template or substrate. A dielectric layer with “window” openings or trenches provides significant suppression of all diagonally running defects during growth. Posts of appropriate height and spacing may further provide suppression of vertically running defects. A layer including gallium nitride is formed over the dielectric layer, and polished to provide a planar growth surface with desired roughness. A tri-layer indium gallium nitride active region is employed. For laser diode embodiments, a relatively thick aluminum gallium nitride cladding layer is provided over the gallium nitride layer. | 12-01-2011 |
20110303891 | Mixed Alloy Defect Redirection Region and Devices Including Same - An optical semiconductor device such as a light emitting diode is formed on a transparent substrate having formed thereon a template layer, such as AlN, which is transparent to the wavelength of emission of the optical device. A mixed alloy defect redirection region is provided over the template layer such that the composition of the defect redirection region approaches or matches the composition of the regions contiguous thereto. For example, the Al content of the defect redirection region may be tailored to provide a stepped or gradual Aluminum content from template to active layer. Strain-induced cracking and defect density are reduced or eliminated. | 12-15-2011 |
20110318880 | CONTACT SPRING APPLICATION TO SEMICONDUCTOR DEVICES - A contact spring applicator is provided which includes an applicator substrate, a removable encapsulating layer and a plurality of contact springs embedded in the removable encapsulating layer. The contact springs are positioned such that a bond pad on each contact spring is adjacent to an upper surface of the removable encapsulating layer. The contact spring applicator may also include an applicator substrate, a release layer, a plurality of unreleased contact springs on the release layer and a bond pad at an anchor end of each contact spring. The contact spring applicators apply contact springs to an integrated circuit chip, die or package or to a probe card by aligning the bond pads with bond pad landings on the receiving device. The bond pads are adhered to the bond pad landings. The encapsulating or release layer is then removed to separate the contact springs from the contact spring applicator substrate. | 12-29-2011 |
20120088330 | AIRGAP MICRO-SPRING INTERCONNECT WITH BONDED UNDERFILL SEAL - A method of assembling a package includes aligning a pad chip with a spring chip to form at least one interconnect in an interconnect area, adhering the pad chip to the spring chip so that there is a gap between the pad chip and the spring chip, dispensing underfill material into the gap to seal the interconnect area from an environment external to the package, and curing the underfill material to form a solid mold. | 04-12-2012 |
20120273750 | LIGHT EMITTING DEVICES HAVING DOPANT FRONT LOADED TUNNEL BARRIER LAYERS - Light emitting devices described herein include dopant front loaded tunnel barrier layers (TBLs). A front loaded TBL includes a first surface closer to the active region of the light emitting device and a second surface farther from the active region. The dopant concentration in the TBL is higher near the first surface of the TBL when compared to the dopant concentration near the second surface of the TBL. The front loaded region near the first surface of the TBL is formed during fabrication of the device by pausing the growth of the light emitting device before the TBL is formed and flowing dopant into the reaction chamber. After the dopant flows in the reaction chamber during the pause, the TBL is grown. | 11-01-2012 |
20120280212 | Semi-Polar Nitride-Based Light Emitting Structure and Method of Forming Same - A structure and method for producing same provides a solid-state light emitting device with suppressed lattice defects in epitaxially formed nitride layers over a non-c-plane oriented (e.g., semi-polar) template or substrate. A dielectric layer with “window” openings or trenches provides significant suppression of all diagonally running defects during growth. Posts of appropriate height and spacing may further provide suppression of vertically running defects. A layer including gallium nitride is formed over the dielectric layer, and polished to provide a planar growth surface with desired roughness. A tri-layer indium gallium nitride active region is employed. For laser diode embodiments, a relatively thick aluminum gallium nitride cladding layer is provided over the gallium nitride layer. | 11-08-2012 |
20130016746 | Vertical Surface Emitting Semiconductor Device - A semiconductor light emitting device includes a pump light source, a gain structure, and an out-coupling mirror. The gain structure is comprised of InGaN layers that have resonant excitation absorption at the pump wavelength. Light from the pump light source causes the gain structure to emit light, which is reflected by the out-coupling mirror back to the gain structure. A distributed Bragg reflector causes internal reflection within the gain structure. The out-coupling mirror permits light having sufficient energy to pass therethrough for use external to the device. A frequency doubling structure may be disposed between the gain structure and the out-coupling mirror. Output wavelengths in the deep-UV spectrum may be achieved. | 01-17-2013 |
20130052758 | REMOVING ALUMINUM NITRIDE SECTIONS - Approaches for substantially removing bulk aluminum nitride (AlN) from one or more layers epitaxially grown on the bulk AlN are discussed. The bulk AlN is exposed to an etchant during an etching process. During the etching process, the thickness of the bulk AlN can be measured and used to control etching. | 02-28-2013 |
20130082237 | ULTRAVIOLET LIGHT EMITTING DEVICES HAVING ENHANCED LIGHT EXTRACTION - Light emitting devices having an enhanced degree of polarization, P | 04-04-2013 |
20130099141 | ULTRAVIOLET LIGHT EMITTING DEVICE INCORPORTING OPTICALLY ABSORBING LAYERS - A light emitting device includes a p-side, an n-side, and an active layer between the p-side and the n-side. The p-side includes a p-side contact, an electron blocking layer, a p-side separate confinement heterostructure (p-SCH), and a p-cladding/current spreading region disposed between the p-SCH and the p-side contact. The n-side includes an n-side contact, and an n-side separate confinement heterostructure (n-SCH). The active layer is configured to emit light in a wavelength range, wherein the p-side and the n-side have asymmetrical optical transmission properties with respect to the wavelength range emitted by the active layer. | 04-25-2013 |
20130196471 | STRESS-ENGINEERED INTERCONNECT PACKAGES WITH ACTIVATOR-ASSISTED MOLDS - A method includes providing a pad chip having contact pads, providing a spring chip having micro-springs, applying a chemical activator to one of either the pad chip or the spring chip, applying an adhesive responsive to the chemical activator on the other of the pad chip or the spring chip, aligning the pad chip to the spring chip such that the micro-springs will contact the contact pads, and pressing the pad chip and the spring chip together such that the chemical activator at least partially cures the adhesive. | 08-01-2013 |
20140038334 | LASER-INDUCED FLAW FORMATION IN NITRIDE SEMICONDUCTORS - An embodiment is a method to induce flaw formation in nitride semiconductors. Regions of a thin film structure are selectively decomposed within a thin film layer at an interface with a substrate to form flaws in a pre-determined pattern within the thin film structure. The flaws locally concentrate stress in the pre-determined pattern during a stress-inducing operation. The stress-inducing operation is performed. The stress-inducing operation causes the thin film layer to fracture at the pre-determined pattern. | 02-06-2014 |
20140231745 | P-SIDE LAYERS FOR SHORT WAVELENGTH LIGHT EMITTERS - A light emitting device includes a p-side heterostructure having a short period superlattice (SPSL) formed of alternating layers of Al | 08-21-2014 |
20140367636 | ULTRAVIOLET LIGHT EMITTING DEVICE INCORPORATING OPTICALLY ABSORBING LAYERS - A light emitting device includes a p-side, an n-side, and an active layer between the p-side and the n-side. The p-side includes a p-side contact, an electron blocking layer, a p-side separate confinement heterostructure (p-SCH), and a p-cladding/current spreading region disposed between the p-SCH and the p-side contact. The n-side includes an n-side contact, and an n-side separate confinement heterostructure (n-SCH). The active layer is configured to emit light in a wavelength range, wherein the p-side and the n-side have asymmetrical optical transmission properties with respect to the wavelength range emitted by the active layer. | 12-18-2014 |
20140369367 | Structure For Electron-Beam Pumped Edge-Emitting Device and Methods for Producing Same - A semiconductor light emitting device includes a light guiding structure, a light emitting layer disposed within the light guiding structure, and a structure for discharging excess electric charge within the device. The device may be excited by an electron beam, as opposed to an optical beam, to create electron-hole pairs. The light emitting layer is configured for light generation without requiring a p-n junction, and is therefore not embedded within nor part of a p-n junction. Doping with p-type species is obviated, reducing device loss and permitting operation at a short wavelengths, such as below 300 nm. Various structures, such as a top-side cladding layer, are disclosed for discharging beam-induced charge. A single device may be operated with multiple electron beam pumps, either to enable a relatively thick active layer or to drive multiple separate active layers. Cooperatively curved end facets accommodate for possible off-axis resonance within the active region(s). | 12-18-2014 |
20150048397 | TRANSPARENT ELECTRON BLOCKING HOLE TRANSPORTING LAYER - A light emitting diode includes an active region configured to emit light, a composite electrical contact layer, and a transparent electron blocking hole transport layer (TEBHTL). The composite electrical contact layer includes two materials. At least one of the two materials is a metal configured to reflect a portion of the emitted light. The TEBHTL is arranged between the composite electrical contact layer and the active region. The TEBHTL has a thickness that extends at least a majority of a distance between the active region and the composite electrical contact layer. The TEBHTL has a band-gap greater than a band-gap of light emitting portions of the active region. The band-gap of the TEBHTL decreases as a function of distance from the active region to the composite electrical contact layer over a majority of the thickness of the TEBHTL. | 02-19-2015 |