Abstract: A light emitting device includes a semiconductor structure having a light emitting layer disposed between an n-type region and a p-type region. A porous region is disposed between the light emitting layer and a contact electrically connected to one of the n-type region and the p-type region. The porous region scatters light away from the absorbing contact, which may improve light extraction from the device. In some embodiments the porous region is an n-type semiconductor material such as GaN or GaP.

Abstract: A light emitting device comprises a flip-chip light emitting diode (LED) die mounted on a submount. The top surface of the submount has a reflective layer. Over the LED die is molded a hemispherical first transparent layer. A low index of refraction layer is then provided over the first transparent layer to provide TIR of phosphor light. A hemispherical phosphor layer is then provided over the low index layer. A lens is then molded over the phosphor layer. The reflection achieved by the reflective submount layer, combined with the TIR at the interface of the high index phosphor layer and the underlying low index layer, greatly improves the efficiency of the lamp. Other material may be used. The low index layer may be an air gap or a molded layer. Instead of a low index layer, a distributed Bragg reflector may be sputtered over the first transparent layer.

Abstract: A photonic crystal is grown within a semiconductor structure, such as a III-nitride structure, which includes a light emitting region disposed between an n-type region and a p-type region. The photonic crystal may be multiple regions of semiconductor material separated by a material having a different refractive index than the semiconductor material. For example, the photonic crystal may be posts of semiconductor material grown in the structure and separated by air gaps or regions of masking material. Growing the photonic crystal, rather than etching a photonic crystal into an already-grown semiconductor layer, avoids damage caused by etching which may reduce efficiency, and provides uninterrupted, planar surfaces on which to form electric contacts.

Abstract: A light emitting device includes a number of light emitting diode dies (LEDs) mounted on a shared submount and covered with a single lens element that includes a corresponding number of lens elements. The LEDs are separated from each other by a distance that is sufficient for lens element to include separate lens elements for each LED. The separation of the LEDs and lens elements may be configured to produce a desired amount of light on a target at a predefined distance. In one embodiment, the lens elements are approximately flat type lens elements, such as Fresnel, TIR, diffractive lens, photonic crystal type lenses, prism, or reflective lens.

Abstract: In some embodiments of the invention, a device includes a substrate and a semiconductor structure. The substrate includes a wavelength converting element comprising a wavelength converting material disposed in a transparent material, a seed layer comprising a material on which III-nitride material will nucleate, and a bonding layer disposed between the wavelength converting element and the seed layer. The semiconductor structure includes a III-nitride light emitting layer disposed between an n-type region and a p-type region, and is grown on the seed layer.

Abstract: A device includes a semiconductor structure comprising a light emitting layer disposed between an n-type region and a p-type region. A bottom contact disposed on a bottom surface of the semiconductor structure is electrically connected to one of the n-type region and the p-type region. A top contact disposed on a top surface of the semiconductor structure is electrically connected to the other of the n-type region and the p-type region. A mirror is aligned with the top contact. The mirror includes a trench formed in the semiconductor structure and a reflective material disposed in the trench, wherein the trench extends through the light emitting layer.

Abstract: A semiconductor structure includes a light emitting layer disposed between an n-type region and a p-type region. A p-electrode is disposed on a portion of the p-type region. The p-electrode includes a reflective first material in direct contact with a first portion of the p-type region and a second material in direct contact with a second portion of the p-type region adjacent to the first portion. The first material and second material are formed in planar layers of substantially the same thickness.

Abstract: A device is provided with at least one light emitting device (LED) die mounted on a submount with an optical element subsequently thermally bonded to the LED die. The LED die is electrically coupled to the submount through contact bumps that have a higher temperature melting point than is used to thermally bond the optical element to the LED die. In one implementation, a single optical element is bonded to a plurality of LED dice that are mounted to the submount and the submount and the optical element have approximately the same coefficients of thermal expansion. Alternatively, a number of optical elements may be used. The optical element or LED die may be covered with a coating of wavelength converting material. In one implementation, the device is tested to determine the wavelengths produced and additional layers of the wavelength converting material are added until the desired wavelengths are produced.

Abstract: A semiconductor light emitting device comprises a light emitting layer disposed between an n-type region and a p-type region. The light emitting layer is adapted to emit first light having a first peak wavelength. A first wavelength converting material is adapted to absorb the first light and emit second light having a second peak wavelength. A second wavelength converting material is adapted to absorb either the first light or the second light and emit third light having a third peak wavelength. A filter is adapted to reflect fourth light having a fourth peak wavelength. The fourth light is either a portion of the second light or a portion of the third light. The filter is configured to transmit light having a peak wavelength longer or shorter than the fourth peak wavelength. The filter is disposed over the light emitting device in the path of at least a portion of the first, second, and third light.

Abstract: Backlights containing low profile, side-emitting LEDs are described that have improved brightness uniformity. In one embodiment, the backlight comprises a solid transparent lightguide with a plurality of openings in a bottom surface of the lightguide, each opening containing a side-emitting LED. Prisms or other optical features are formed in the top wall of each opening to reflect light in the lightguide towards a light output surface of the lightguide so that the side-emitting LEDs do not appear as dark spots at the output of the backlight. To avoid any direct emission from the sides of the LED toward the output surface of the lightguide appearing as bright areas, optical features are formed at the edges of the opening or in the output surface of the lightguide so that direct emission light is not output from the lightguide. Substantially identical cells may be formed in the lightguide using cellular walls around one or more LEDs.

Abstract: A method according to embodiments of the invention includes providing a substrate comprising a host and a seed layer bonded to the host. The seed layer comprises a plurality of regions. A semiconductor structure comprising a light emitting layer disposed between an n-type region and a p-type region is grown on the substrate. A top surface of a semiconductor layer grown on the seed layer has a lateral extent greater than each of the plurality of seed layer regions.

Abstract: Embodiments of the invention include a III-nitride semiconductor structure comprising a light emitting region disposed between an n-type region and a p-type region. At least one layer in the light emitting region is Bx(InyGa1-y)1-xN. In some embodiments, x is less than 14%. In some embodiments, the BN composition is selected such that the Bx(InyGa1-y)1-xN layer has the same band gap energy as a comparable InGaN layer, with a bulk lattice constant that is the same or smaller than the comparable InGaN layer.

Abstract: Low profile, side-emitting LEDs are described that generate white light, where all light is emitted within a relatively narrow angle generally parallel to the surface of the light-generating active layer. The LEDs enable the creation of very thin backlights for backlighting an LCD. In one embodiment, the LED emits blue light and is a flip chip with the n and p electrodes on the same side of the LED. Separately from the LED, a transparent wafer has deposited on it a red and green phosphor layer. The phosphor color temperature emission is tested, and the color temperatures vs. positions along the wafer are mapped. A reflector is formed over the transparent wafer. The transparent wafer is singulated, and the phosphor/window dice are matched with the blue LEDs to achieve a target white light color temperature. The phosphor/window is then affixed to the LED.

Abstract: A semiconductor structure includes a light emitting layer disposed between an n-type region and a p-type region. A p-electrode is disposed on a portion of the p-type region. The p-electrode includes a reflective first material in direct contact with a first portion of the p-type region and a second material in direct contact with a second portion of the p-type region adjacent to the first portion. The first material and second material are formed in planar layers of substantially the same thickness.

Abstract: In embodiments of the invention, a passivation layer is disposed over a side of a semiconductor structure including a light emitting layer disposed between an n-type region and a p-type region. A material configured to adhere to an underfill is disposed over an etched surface of the semiconductor structure.

Abstract: Embodiments of the invention include a semiconductor light emitting device capable of emitting first light having a first peak wavelength and a wavelength converting element capable of absorbing the first light and emitting second light having a second peak wavelength. In some embodiments, the structure further includes a metal nanoparticle array configured to pass a majority of light in a first wavelength range and reflect or absorb a majority of light in a second wavelength range. In some embodiments, the structure further includes a filter configured to pass a majority of light in a first wavelength range and reflect or absorb a majority of light in a second wavelength range, wherein the filter is configured such that a wavelength at which a minimum amount of light is passed by the filter shifts no more than 30 nm for light incident on the filter at angles between 0° and 60° relative to a normal to a major surface of the filter.

Abstract: A device is provided with an array of a plurality of phosphor converted light emitting devices (LEDs) that produce broad spectrum light. The phosphor converted LEDs may produce light with different correlated color temperature (CCT) and are covered with an optical element that assists in mixing the light from the LEDs to produce a desired correlated color temperature. The optical element may be bonded to the phosphor converted light emitting devices. The optical element may be a dome mounted over the phosphor converted light emitting devices and filled with an encapsulant.

Abstract: In some embodiments of the invention, a device includes a first semiconductor layer, a second semiconductor layer, a third semiconductor layer, and a semiconductor structure comprising a III-nitride light emitting layer disposed between an n-type region and a p-type region. The second semiconductor layer is disposed between the first semiconductor layer and the third semiconductor layer. The third semiconductor layer is disposed between the second semiconductor layer and the light emitting layer. A difference between the in-plane lattice constant of the first semiconductor layer and the bulk lattice constant of the third semiconductor layer is no more than 1%. A difference between the in-plane lattice constant of the first semiconductor layer and the bulk lattice constant of the second semiconductor layer is at least 1%. The third semiconductor layer is at least partially relaxed.

Abstract: A method according to embodiments of the invention includes providing an epitaxial structure comprising a donor layer and a strained layer. The epitaxial structure is treated to cause the strained layer to relax. Relaxation of the strained layer causes an in-plane lattice constant of the donor layer to change.

Abstract: A process for preparing a semiconductor light-emitting device for mounting is disclosed. The light-emitting device has a mounting face for mounting to a sub-mount. The process involves treating at least one surface of the light-emitting device other than the mounting face to lower a surface energy of the at least one surface, such that when mounting the light-emitting device, an underfill material applied between the mounting face and the sub-mount is inhibited from contaminating the at least one surface.