Abstract: Affixed over a transparent growth substrate (34) of an LED die (30) is a transparent rectangular pillar (40), having a footprint approximately the same size as the LED die. The pillar height is greater than a length of the LED die, and the pillar has an index (n) approximately equal to that of the substrate (e.g., 1.8), so there is virtually no TIR at the interface due to the matched indices. Surrounding the pillar and the LED die is a lens portion (42) having a diameter between 1.5-3 times the length of the LED die. The index of the lens portion is about 0.8 times the index of the substrate. The lens portion may have a dome shape (46). A large portion of the light exiting the substrate is internally reflected off the lateral pillar/cylinder interface and exits the top surface of the pillar. Thus, the emission is narrowed and light extraction efficiency is increased.

Abstract: Application of a wavelength conversion element is substantially independent of the fabrication of a side-emitting light emitting device. In an example embodiment, the wavelength conversion element is situated around the periphery of a non-wavelength converting lightguide that is situated above the light emitting surface. One or more specular and/or diffusing reflectors are used to direct the light in the lightguide toward the wavelength conversion element at the periphery. In another embodiment, an interference filter may be used to provide predominantly side-emitted light at interfaces between the elements of the light emitting device.

Abstract: In one embodiment, the transparent growth substrate (38) of an LED die is formed to have light scattering areas (40A-C), 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 (42A, 42B) of the substrate to reduce light guiding. Another embodiment comprises a replacement substrate may be formed to include reflective particles in selected areas where there are no corresponding light generating areas in the LED semiconductor layers such as—type metal contacts (28). This prevents reabsorption into absorbing regions of the semiconductor layer thereby enhancing external efficiency of the device. A 3D structure may be formed by stacking substrate layers containing the reflective areas.

Abstract: A structure according to embodiments of the invention includes a semiconductor light emitting device and an optical element disposed over the semiconductor light emitting device. The semiconductor light emitting device is disposed in a recess in the optical element. A reflector is disposed on a bottom surface of the optical element. A method according to embodiments of the invention includes disposing a semiconductor light emitting device on a substrate and forming a reflector adjacent the semiconductor light emitting device. An optical element is formed over the semiconductor light emitting device. The semiconductor light emitting device is removed from the substrate.

Abstract: Embodiments of the invention include a semiconductor light emitting diode (LED) attached to a top surface of a mount. A multi-layer reflector is disposed on the top surface of the mount adjacent to the LED. The multi-layer reflector includes layer pairs of alternating layers of low index of refraction material and high index of refraction material. A portion of the top surface in direct contact with the multi-layer reflector is non-reflective.

Abstract: To reduce absorption by an LED die (12) of light emitted by a phosphor layer (48), the absorbing semiconductor layers of the LED die (12) are separated from the phosphor layer by a relatively thick glass plate (44) affixed to the LED die or by the LED die transparent growth substrate. Therefore, phosphor light emitted at a sufficient angle towards the LED die will pass through the transparent spacer (44) and exit the sidewalls of the spacer, preventing the light from being absorbed by the LED die. The LED die may be GaN based. The spacer is at least 100 microns thick. A 16% gain in light extraction is achievable using the technique compared to the light emission where phosphor is directly deposited on the LED semiconductor layers.

Abstract: Embodiments of the invention include a semiconductor light emitting device, a first wavelength converting member disposed on a top surface of the semiconductor light emitting device, and a second wavelength converting member disposed on a side surface of the semiconductor light emitting device. The first and second wavelength converting members include different wavelength converting materials.

Abstract: Embodiments of the invention include a semiconductor light emitting diode attached to a substrate. A first region of wavelength converting material is disposed on the substrate. The wavelength converting material is configured to absorb light emitted by the semiconductor light emitting diode and emit light at a different wavelength. In the first region, the wavelength converting material coats an entire surface of the substrate. The substrate is disposed proximate a bottom surface of an optical cavity. A second region of wavelength converting material is disposed proximate a top surface of the optical cavity.