Abstract:
A semiconductor structure comprises a light emitting layer (14) disposed between an n- type region (12) and a p-type region (16). A wavelength converting material (26) is disposed over the semiconductor structure. The wavelength converting material (26) is configured to absorb light emitted by the semiconductor structure and emit light of a different wavelength. A filter (28) configured to reflect blue ambient light is disposed over the wavelength converting material (26). A scattering structure (36) is disposed over the wavelength converting layer (26). The scattering structure (36) is configured to scatter light In some embodiments, the scattering structure (36) is a transparent' material having a rough surface, containing non-wavelength-converting particles that appear substantially white in ambient light, or including both a rough surface and white particles.
Abstract:
A white light LED is described that uses an LED die that emits visible blue light in a wavelength range of about 450-470 nm. A red phosphor or quantum dot material converts some of the blue light to a visible red light having a peak wavelength between about 605-625 nm with a full-width-half-maximum (FWHM) less than 80nm. A green phosphor or quantum dot material converts some of the blue light to a green light having a FWHM greater than 40nm, wherein the combination of the blue light, red light, and green light produces a white light providing a color rendering of R a,8 >90 and a color temperature of between 2500K-5000K. Preferably, the red and green converting material do not saturate with an LED die output of 100 W/cm 2 and can reliably operate with an LED die junction temperature over 100 degrees C.
Abstract translation:描述了使用发射在约450-470nm的波长范围内的可见蓝光的LED管芯的白光LED。 红色荧光体或量子点材料将一些蓝色光转换成具有在约605-625nm之间的峰值波长和小于80nm的全宽半最大值(FWHM)的可见红光。 绿色荧光体或量子点材料将一些蓝色光转换成具有大于40nm的FWHM的绿色光,其中蓝色光,红色光和绿色光的组合产生白色光,提供Ra,8的显色性 > 90°,色温在2500K-5000K之间。 优选地,红色和绿色转换材料对于100W / cm 2的LED管芯输出不饱和,并且可以在LED管芯结温超过100摄氏度时可靠地工作。
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:
A semiconductor light emitting device (34) 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 (38) is adapted to absorb the first light and emit second light having a second peak wavelength. A second wavelength converting material (36) is adapted to absorb either the first light or the second light and emit third light having a third peak wavelength. A filter (40) 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:
In accordance with embodiments of the invention, strain is reduced in the light emitting layer of a Ill-nitride device by including a strain-relieved layer in the device. The surface on which the strain-relieved layer is grown is configured such that strain-relieved layer can expand laterally and at least partially relax. In some embodiments of the invention, the strain-relieved layer is grown over a textured semiconductor layer or a mask layer. In some embodiments of the invention, the strain-relieved layer is group of posts of semiconductor material.
Abstract:
A compliant bonding structure is disposed between a semiconductor light emitting device and a mount (40). When the semiconductor light emitting device is attached to the mount, for example by providing pressure, heat, and/or ultrasonic energy to the semiconductor light emitting device, the compliant bonding structure collapses to partially fill a space between the semiconductor light emitting device and the mount. In some embodiments, the compliant bonding structure is plurality of metal bumps (32) that undergo plastic deformation during bonding. In some embodiments, the compliant bonding structure is a porous metal layer (46).
Abstract:
Methods of fabricating relaxed layers of semiconductor materials include forming structures of a semiconductor material overlying a layer of a compliant material, and subsequently altering a viscosity of the compliant material to reduce strain within the semiconductor material. The compliant material may be reflowed during deposition of a second layer of semiconductor material. The compliant material may be selected so that, as the second layer of semiconductor material is deposited, a viscosity of the compliant material is altered imparting relaxation of the structures. In some embodiments, the layer of semiconductor material may comprise a III-V type semiconductor material, such as, for example, indium gallium nitride. Methods of fabricating semiconductor structures and devices are also disclosed. Novel intermediate structures are formed during such methods. Engineered substrates include a plurality of structures comprising a semiconductor material disposed on a layer of material exhibiting a changeable viscosity.
Abstract:
A plurality of III-nitride semiconductor structures, each comprising a light emitting layer disposed between an n-type region and a p-type region, are grown on a composite substrate. The composite substrate includes a plurality of islands of III-nitride material connected to a host by a bonding layer. The plurality of III-nitride semiconductor structures are grown on the III-nitride islands. The composite substrate may be formed such that each island of III-nitride material is at least partially relaxed. As a result, the light emitting layer of each semiconductor structure has an a-lattice constant greater than 3.19 angstroms.
Abstract:
In accordance with embodiments of the invention, strain is reduced in the light emitting layer of a Ill-nitride device by including a strain-relieved layer in the device. The surface on which the strain-relieved layer is grown is configured such that strain-relieved layer can expand laterally and at least partially relax. In some embodiments of the invention, the strain-relieved layer is grown over a textured semiconductor layer or a mask layer. In some embodiments of the invention, the strain-relieved layer is group of posts of semiconductor material.
Abstract:
An LED pump light with multiple phosphors is described. LEDs emitting radiation at violet and/or ultraviolet wavelengths are used to pump phosphor materials that emit other colors. The LEDs operating in different wavelength ranges are arranged to reduce light re-absorption and improve light output efficiency.