Abstract: A structure includes a semiconductor light emitting device including a light emitting layer disposed between an n-type region and a p-type region. The light emitting layer emits first light of a first peak wavelength. A wavelength-converting material that absorbs the first light and emits second light of a second peak wavelength is disposed in the path of the first light. A filter material that transmits a portion of the first light and absorbs or reflects a portion of the first light is disposed over the wavelength-converting material.

Abstract: A III-nitride light-emitting structure including a p-type layer, an n-type layer, and a light emitting layer is grown on a growth substrate. The III-nitride light-emitting structure is wafer bonded to a host substrate, then the growth substrate is removed. In some embodiments, a first electrical contact and first bonding layer are formed on the III-nitride light-emitting structure. A second bonding layer is formed on the host substrate. In such embodiments, wafer bonding the III-nitride light emitting structure to the host substrate comprises bonding the first bonding layer to the second bonding layer. After the growth substrate is removed, a second electrical contact may be formed on a side of the III-nitride light-emitting device exposed by removal of the growth substrate.

Abstract: A light-emitting semiconductor device includes a stack of layers including an active region. The active region includes a semiconductor selected from the group consisting of III-Phosphides, III-Arsenides, and alloys thereof. A superstrate substantially transparent to light emitted by the active region is disposed on a first side of the stack. First and second electrical contacts electrically coupled to apply a voltage across the active region are disposed on a second side of the stack opposite to the first side. In some embodiments, a larger fraction of light emitted by the active region exits the stack through the first side than through the second side. Consequently, the light-emitting semiconductor device may be advantageously mounted as a flip chip to a submount, for example.

Abstract: A light emitting device includes a semiconductor light emitting device chip having a top surface and a side surface, a wavelength-converting material overlying at least a portion of the top surface and the side surface of the chip, and a filter material overlying the wavelength-converting material. The chip is capable of emitting light of a first wavelength, the wavelength-converting material is capable of absorbing light of the first wavelength and emitting light of a second wavelength, and the filter material is capable of absorbing light of the first wavelength. In other embodiments, a light emitting device includes a filter material capable of reflecting light of a first wavelength and transmitting light of a second wavelength.

Abstract: A light-emitting device includes: a semiconductor structure formed on one side of a substrate, the semiconductor structure having a plurality of semiconductor layers and an active region within the layers; and first and second conductive electrodes contacting respectively different semiconductor layers of the structure; the substrate comprising a material having a refractive index n>2.0 and light absorption coefficient &agr;, at the emission wavelength of the active region, of &agr;>3 cm−1. In a preferred embodiment, the substrate material has a refractive index n>2.3, and the light absorption coefficient, &agr;, of the substrate material is &agr;<1 cm−1.

Abstract: A III-nitride light-emitting structure including a p-type layer, an n-type layer, and a light emitting layer is grown on a growth substrate. The III-nitride light-emitting structure is wafer bonded to a host substrate, then the growth substrate is removed. In some embodiments, a first electrical contact and first bonding layer are formed on the III-nitride light-emitting structure. A second bonding layer is formed on the host substrate. In such embodiments, wafer bonding the III-nitride light emitting structure to the host substrate comprises bonding the first bonding layer to the second bonding layer. After the growth substrate is removed, a second electrical contact may be formed on a side of the III-nitride light-emitting device exposed by removal of the growth substrate.

Abstract: A light emitting device includes a semiconductor light emitting device chip having a top surface and a side surface, a wavelength-converting material overlying at least a portion of the top surface and the side surface of the chip, and a filter material overlying the wavelength-converting material. The chip is capable of emitting light of a first wavelength, the wavelength-converting material is capable of absorbing light of the first wavelength and emitting light of a second wavelength, and the filter material is capable of absorbing light of the first wavelength. In other embodiments, a light emitting device includes a filter material capable of reflecting light of a first wavelength and transmitting light of a second wavelength.

Abstract: A light emitting device including a nucleation layer containing aluminum is disclosed. The thickness and aluminum composition of the nucleation layer are selected to match the index of refraction of the substrate and device layers, such that 90% of light from the device layers incident on the nucleation layer is extracted into the substrate. In some embodiments, the nucleation layer is AlGaN with a thickness between about 1000 and about 1200 angstroms and an aluminum composition between about 2% and about 8%. In some embodiments, the nucleation layer is formed over a surface of a wurtzite substrate that is miscut from the c-plane of the substrate. In some embodiments, the nucleation layer is formed at high temperature, for example between 900° and 1200° C. In some embodiments, the nucleation layer is doped with Si to a concentration between about 3e18 cm−3 and about 5e19 cm−3.

Abstract: A light-emitting device includes: a semiconductor structure formed on one side of a substrate, the semiconductor structure having a plurality of semiconductor layers and an active region within the layers; and first and second conductive electrodes contacting respectively different semiconductor layers of the structure; the substrate comprising a material having a refractive index n>2.0 and light absorption coefficient &agr;, at the emission wavelength of the active region, of &agr;>3 cm−1. In a preferred embodiment, the substrate material has a refractive index n>2.3, and the light absorption coefficient, &agr;, of the substrate material is &agr;<1 cm−1.

Abstract: A light source is disclosed that includes a light emitting device such as a III-nitride light emitting diode covered with a luminescent material structure, such as a single layer or multiple layers of phosphor. Any variations in the thickness of the luminescent material structure are less than or equal to 10% of the average thickness of the luminescent material structure. In some embodiments, the thickness of the luminescent material structure is less than 10% of a cross-sectional dimension of the light emitting device. In some embodiments, the luminescent material structure is the only luminescent material through which light emitted from the light emitting device passes. In some embodiments, the luminescent material structure is between about 15 and about 100 microns thick. The luminescent material structure is selectively deposited on the light emitting device by, for example, stenciling or electrophoretic deposition.

Abstract: A photonic crystal light emitting diode (“PXLED”) is provided. The PXLED includes a periodic structure, such as a lattice of holes, formed in the semiconductor layers of an LED. The parameters of the periodic structure are such that the energy of the photons, emitted by the PXLED, lies close to a band edge of the band structure of the periodic structure. Metal electrode layers have a strong influence on the efficiency of the PXLEDs. Also, PXLEDs formed from GaN have a low surface recombination velocity and hence a high efficiency. The PXLEDs are formed with novel fabrication techniques, such as the epitaxial lateral overgrowth technique over a patterned masking layer, yielding semiconductor layers with low defect density. Inverting the PXLED to expose the pattern of the masking layer or using the Talbot effect to create an aligned second patterned masking layer allows the formation of PXLEDs with low defect density.

Abstract: Presented is a method of conformally coating a light emitting semiconductor structure with a phosphor layer to produce a substantially uniform white light. A light emitting semiconductor structure is coupled to a submount, a first bias voltage is applied to the submount, and a second bias voltage is applied to a solution of charged phosphor particles. The charged phosphor particles deposit on the conductive surfaces of the light emitting semiconductor structure. If the light emitting semiconductor structure includes a nonconductive substrate, the light emitting semiconductor structure is coated with an electroconductive material to induce phosphor deposition. The electrophoretic deposition of the phosphor particles creates a phosphor layer of uniform thickness that produces uniform white light without colored rings.

Abstract: The invention is a method for designing semiconductor light emitting devices such that the side surfaces (surfaces not parallel to the epitaxial layers) are formed at preferred angles relative to vertical (normal to the plane of the light-emitting active layer) to improve light extraction efficiency and increase total light output efficiency. Device designs are chosen to improve efficiency without resorting to excessive active area-yield loss due to shaping. As such, these designs are suitable for low-cost, high-volume manufacturing of semiconductor light-emitting devices with improved characteristics.

Abstract: A light emitting device including a nucleation layer containing aluminum is disclosed. The thickness and aluminum composition of the nucleation layer are selected to match the index of refraction of the substrate and device layers, such that 90% of light from the device layers incident on the nucleation layer is extracted into the substrate. In some embodiments, the nucleation layer is AlGaN with a thickness between about 1000 and about 1200 angstroms and an aluminum composition between about 2% and about 8%. In some embodiments, the nucleation layer is formed over a surface of a wurtzite substrate that is miscut from the c-plane of the substrate. In some embodiments, the nucleation layer is formed at high temperature, for example between 900° and 1200° C. In some embodiments, the nucleation layer is doped with Si to a concentration between about 3e18 cm−3 and about 5e19 cm−3.

Abstract: A method of forming a light emitting semiconductor device includes fabricating a stack of layers comprising an active region, and wafer bonding a structure including a carrier confinement semiconductor layer to the stack. A light emitting semiconductor device includes a first carrier confinement layer of a first semiconductor having a first conductivity type, an active region, and a wafer bonded interface disposed between the active region and the first carrier confinement layer. The light emitting semiconductor device may further include a second carrier confinement layer of a second semiconductor having a second conductivity type, with the active region disposed between the first carrier confinement layer and the second carrier confinement layer. The wafer bonded confinement layer provides enhanced carrier confinement and device performance.

Abstract: The present invention is an inverted III-nitride light-emitting device (LED) with enhanced total light generating capability. A large area device has an n-electrode that interposes the p-electrode metallization to provide low series resistance. The p-electrode metallization is opaque, highly reflective, and provides excellent current spreading. The p-electrode at the peak emission wavelength of the LED active region absorbs less than 25% of incident light per pass. A submount may be used to provide electrical and thermal connection between the LED die and the package. The submount material may be Si to provide electronic functionality such as voltage-compliance limiting operation. The entire device, including the LED-submount interface, is designed for low thermal resistance to allow for high current density operation. Finally, the device may include a high-refractive-index (n>1.8) superstrate.

Abstract: The present invention is an inverted III-nitride light-emitting device (LED) with enhanced total light generating capability. A large area device has an n-electrode that interposes the p-electrode metallization to provide low series resistance. The p-electrode metallization is opaque, highly reflective, and provides excellent current spreading. The p-electrode at the peak emission wavelength of the LED active region absorbs less than 25% of incident light per pass. A submount may be used to provide electrical and thermal connection between the LED die and the package. The submount material may be Si to provide electronic functionality such as voltage-compliance limiting operation. The entire device, including the LED-submount interface, is designed for low thermal resistance to allow for high current density operation. Finally, the device may include a high-refractive-index (n>1.8) superstrate.

Abstract: A light emitting device and a method of increasing the light output of the device utilize a chirped multi-well active region to increase the probability of radiative recombination of electrons and holes within the light emitting active layers of the active region by altering the electron and hole distribution profiles within the light emitting active layers of the active region (i.e., across the active region). The chirped multi-well active region produces a higher and more uniform distribution of electrons and holes throughout the active region of the device by substantially offsetting carrier diffusion effects caused by differences in electron and hole mobility by using complementary differences in layer thickness and/or layer composition within the active region.

Abstract: In accordance with embodiments of the invention, a light emitting device includes a light emitting region and a reflective contact separated from the light emitting region by one or more layers. In a first embodiment, the separation between the light emitting region and the reflective contact is between about 0.5&lgr;n and about 0.9&lgr;n, where &lgr;n is the wavelength of radiation emitted from the light emitting region in an area of the device separating the light emitting region and the reflective contact. In a second embodiment, the separation between the light emitting region and the reflective contact is between about &lgr;n and about 1.4&lgr;n. The light emitting region may be, for example, III-nitride, III-phosphide, or any other suitable material.

Abstract: A light source is disclosed that includes a light emitting device such as a III-nitride light emitting diode covered with a luminescent material structure, such as a single layer or multiple layers of phosphor. Any variations in the thickness of the luminescent material structure are less than or equal to 10% of the average thickness of the luminescent material structure. In some embodiments, the thickness of the luminescent material structure is less than 10% of a cross-sectional dimension of the light emitting device. In some embodiments, the luminescent material structure is the only luminescent material through which light emitted from the light emitting device passes. In some embodiments, the luminescent material structure is between about 15 and about 100 microns thick. The luminescent material structure is selectively deposited on the light emitting device by, for example, stenciling or electrophoretic deposition.