Abstract: The structural characteristics of the light-exiting surface of a light emitting device are controlled so as to increase the light extraction efficiency of that surface when the surface is roughened. A light emitting surface comprising layers of materials with different durability to the roughening process exhibits a higher light extraction efficiency than a substantially uniform light emitting surface exposed to the same roughening process. In a GaN-type light emitting device, a thin layer of AlGaN material on or near the light-exiting surface creates sharper features after etching compared to the features created by conventional etching of a surface comprising only GaN material.

Abstract: A control circuit for a light emitting diode (LED) lighting system for achieving a dim-to-warm effect is provided. The control circuit includes an LED controller, a clamp circuit coupled to a set of warm correlated-color-temperature (“CCT”) LEDs, a switch coupled to a set of cool LEDs, and a feedback circuit coupled to the clamp and the switch. The LED controller is configured to control the clamp circuit to clamp current through the set of warm LEDs based on the input current, and control the switch to switch on the set of cool LEDs responsive to the input current being greater than a first threshold level and to switch off the set of cool LEDs responsive to the input current being lower than the first threshold level. The feedback circuit is configured to divert current from the set of warm LEDs to the set of cool LEDs.

Abstract: A system may include a light source. A converter may be configured to convert an AC voltage to a DC operating voltage during normal operation. A power backup device may be coupled to the converter. A current source may have a first terminal configured to receive the DC operating voltage during regular operation and a second terminal configured to provide a pulse-width modulated (PWM) signal to an anode end of the light source. A switching device may have a first connecting terminal coupled to the anode end of the light source, a second connecting terminal coupled to the power backup device, and a control terminal coupled to the converter. The switching device may be configured to open a switch between the first connecting terminal and the second connecting terminal during normal operation and close the switch upon detecting an interruption of the DC operating voltage at the control terminal.

Abstract: A disclosed light-emitting device may provide white light with a cyan gap coinciding with a melanopic sensitivity range and thus having reduced melanopic content. The disclosed light-emitting device may include a light source providing violet or blue light with a peak wavelength under 450 nanometers (nm). The disclosed light-emitting device may include at least one down-converter coupled to and located downstream of the light source and configured with a long-wavelength onset to convert the spectrum of the violet or blue light to generate white light with a spectral power content in a 447-531 nm wavelength range that is less than or equal to 10% of a total spectral power content in a 380-780 nm wavelength range. The disclosed light-emitting device may be incorporated in a light engine system that further includes a control system that controls a drive current to the light-emitting device.

Abstract: The invention provides a luminescent material (10) comprising quantum dots (100), wherein the luminescent material (10) further comprises a capping agent (110) coordinating to the quantum dots (10), wherein the capping agent comprises MxOy(OH)zn, wherein M is selected from the group consisting of B, Al, P, S, V, Zn, Ga, Ge, As, Se, Nb, Mo, Cd, In, Sn, Sb, Te, Ta and W, wherein x?1, y+z?1, and wherein n indicates a positive or negative charge of the capping agent.

Abstract: Pre-formed wavelength conversion elements are attached to light emitting elements and are shaped to reduce repeated occurrences of total internal reflection. The sides of the shaped elements may be sloped or otherwise shaped so as to introduce a change in the angle of incidence of reflected light upon the light extraction surface of the wavelength conversion element. The pre-formed wavelength conversion elements may be configured to extend over an array of light emitting elements, with features between the light emitting elements that are shaped to reduce repeated occurrences of total internal reflection.

Abstract: A light emitting device includes a light emitting element on a substrate, and a lens element that includes a cavity within which the light emitting element is situated, and is optically aligned with the light emitting element. A strip of adhesive that attaches the lens element to the substrate substantially surrounds the light emitting element, but includes a gap that facilitates release of material from the cavity during the attachment of the lens element to the substrate. When the lens element is placed upon the substrate, the adhesive is partially cured to provide a relatively high shear strength before the light emitting device is transported or subjected to other processes. To provide compatibility with subsequent processes or applications, and to protect the light emitting element from the environment, the gap in each device is sealed with a sealing material.

Abstract: Light emitting devices are described herein. A light-emitting device includes a substrate having a surface below an optical cavity, one or more light emitting diodes (LEDs) disposed above the surface of the substrate, a first wavelength-converting layer, and a second wavelength-converting layer. The first wavelength-converting layer is disposed on the surface of the substrate below the optical cavity, covers the entire surface of the substrate except for portions of the surface of the substrate that are situated underneath any of the one or more LEDs, and has a thickness that is equal to or less than a thickness of at least one of the one or more LEDs. The second wavelength-converting layer is disposed above the optical cavity.

Abstract: A device according to embodiments of the invention includes a semiconductor structure including a light emitting layer disposed between an n-type region and a p-type region. A surface of the p-type region perpendicular to a growth direction of the semiconductor structure includes a first portion and a second portion. The first portion is less conductive than the second portion. The device further includes a p-contact formed on the p-type region. The p-contact includes a reflector and a blocking material. The blocking material is disposed over the first portion and no blocking material is disposed over the second portion.

Abstract: Embodiments of the invention include a substrate (10) and a semiconductor structure (12) grown on the substrate. The semiconductor structure includes a light emitting layer (18) disposed between an n-type region (16) and a p-type region (20). The substrate includes a first sidewall (30) and a second sidewall (32). The first sidewall and second sidewall are disposed at different angles relative to a major surface of the semiconductor structure. A reflective layer (34) is disposed over the first sidewall (30).

Abstract: A semiconductor structure comprising a III-nitride light emitting layer disposed between an n-type region and a p-type region is grown over a porous III-nitride region. A III-nitride layer comprising InN is disposed between the light emitting layer and the porous III-nitride region. Since the III-nitride layer comprising InN is grown on the porous region, the III-nitride layer comprising InN may be at least partially relaxed, i.e. the III-nitride layer comprising InN may have an in-plane lattice constant larger than an in-plane lattice constant of a conventional GaN layer grown on sapphire.

Abstract: The present invention relates to a light emitting device (100) comprising: a substrate (102); a light emitting diode structure (106) arranged on the substrate (102), the diode structure (106) comprising a first semiconducting layer (108), an active region (110) and a second semiconducting layer (112), wherein a light output surface of the diode structure comprises a plurality of protruding surface structures (104) each having a peak height, a sidewall slope (122) and orientation in relation to the substrate, the plurality of protruding structures (104) comprising a first set and a second set of protruding surface structures, the first set and second set of protruding surface structures differing by at least one of the peak height, sidewall slope and orientation in relation to the substrate. The invention also relates to a method for manufacturing a light emitting device where the protruding surface structures are formed by imprint lithography to form a three-dimensional pattern and subsequent etching.

Abstract: A lighting structure according to embodiments of the invention includes a semiconductor light emitting device and a flat wavelength converting element attached to the semiconductor light emitting device. The flat wavelength converting element includes a wavelength converting layer for absorbing light emitted by the semiconductor light emitting device and emitting light of a different wavelength. The flat wavelength converting element further includes a transparent layer. The wavelength converting layer is formed on the transparent layer.

Abstract: A method includes forming a reflective layer (202) on a support (110) where the reflective layer (202) defines openings to the support, placing light-emitting diodes (LEDs) (102) through the openings onto the support (110), forming a non-planar secondary light-emitting layer (106) that conforms to the LEDs and the reflective layer (202), forming a planar optically transparent cap layer (108) over the secondary light-emitting layer, and singulating the LEDs into LED units.

Abstract: A method according to embodiments of the invention includes growing on a first surface of a sapphire substrate a semiconductor structure including a light emitting layer disposed between an n-type region and a p-type region. The semiconductor structure is formed into a plurality of LEDs. Cracks are formed in the sapphire substrate. The cracks extend from the first surface of the sapphire substrate and do not penetrate an entire thickness of the sapphire substrate. After forming cracks in the sapphire substrate, the sapphire substrate is thinned from a second surface of the sapphire substrate. The second surface is opposite the first surface.

Abstract: A lighting device and method of forming the lighting device are provided. The lighting device includes a light guide, a lighting element having a light emitting diode (LED), and an in-coupling structure. The in-coupling structure includes one or more remote phosphor regions and one or more reflective regions. The in-coupling structure is integrally formed in a single piece. The in-coupling structure is affixed to the light guide and the lighting element, and is positioned between the light guide and the LED. An optional seal may be a part of the integrally formed in-coupling structure.

Abstract: The surface of a light emitting device is roughened to enhance the light extraction efficiency of the surface, but the amount of roughened area is selected to achieve a desired level of light extraction efficiency. Photo-lithographic techniques may be used to create a mask that limits the roughening to select areas of the light emitting surface. Because the amount of roughened area can be precisely controlled, the light extraction efficiency can be precisely controlled, substantially independent of the particular process used to roughen the surface. Additionally, the selective roughening of the surface may be used to achieve a desired light emission output pattern.

Abstract: In one embodiment, the transparent growth substrate of an LED die is formed to have light scattering areas, such as voids formed by a laser. In another embodiment, the growth substrate is removed and replaced by another substrate that is formed with light scattering areas. In one embodiment, the light scattering areas are formed over the light absorbing areas of the LED die, to reduce the amount of incident light on those absorbing areas, and over the sides of the substrate to reduce light guiding. The replacement substrate may be formed to include reflective particles in selected areas. A 3D structure may be formed by stacking substrate layers containing the reflective areas. The substrate may be a transparent substrate or a phosphor tile that is affixed to the top of the LED.

Abstract: The invention describes an ignitor arrangement (1) for a high-intensity discharge lamp (2), which ignitor arrangement (1) comprises a first pair of input terminals (101, 102) for applying an ignition voltage to the ignitor arrangement (1); a second pair of input terminals (101, 103) for applying an input drive voltage to the ignitor arrangement (1); and a discharge resistor (10) arranged in the interior (100) of the ignitor arrangement (1) and connected across the first input terminal pair (101, 102), which discharge resistor (10) is realized as a temperature-dependent resistor (10). The invention also describes a lamp driver (3) realized to drive a high-intensity discharge lamp (2); a lighting arrangement (4); and a method of driving a high-intensity discharge lamp (2).

Abstract: An LED die conformally coated with phosphor is mounted at the base of a shallow, square reflector cup. The cup has flat reflective walls that slope upward from its base to its rim at a shallow angle of approximately 33 degrees. A clear encapsulant completely fills the cup to form a smooth flat top surface. Any emissions from the LED die or phosphor at a low angle are totally internally reflected at the flat air-encapsulant interface toward the cup walls. This combined LED/phosphor light is then reflected upward by the walls and out of the package. Since a large percentage of the light emitted by the LED and phosphor is mixed by the TIR and the walls prior to exiting the package, the color and brightness of the reflected light is fairly uniform across the beam. The encapsulant is intentionally designed to enhance TIR to help mix the light.