摘要:
A mount for a semiconductor device includes a carrier, at least two metal leads disposed on a bottom surface of the carrier, and a cavity extending through a thickness of the carrier to expose a portion of the top surfaces of the metal leads. A semiconductor light emitting device is positioned in the cavity and is electrically and physically connected to the metal leads. The carrier may be, for example, silicon, and the leads may be multilayer structures, for example a thin gold layer connected to a thick copper layer.
摘要:
A light emitting device includes a light emitting diode (LED), a concentrator element, such as a compound parabolic concentrator, and a wavelength converting material, such as a phosphor. The concentrator element receives light from the LED and emits the light from an exit surface, which is smaller than the entrance surface. The wavelength converting material is, e.g., disposed over the exit surface. The radiance of the light emitting diode is preserved or increased despite the isotropic re-emitted light by the wavelength converting material. In one embodiment, the polarized light from a polarized LED is provided to a polarized optical system, such as a microdisplay. In another embodiment, the orthogonally polarized light from two polarized LEDs is combined, e.g., via a polarizing beamsplitter, and is provided to non-polarized optical system, such as a microdisplay. If desired, a concentrator element may be disposed between the beamsplitter and the microdisplay.
摘要:
A light emitting device includes a light emitting diode (LED), a concentrator element, such as a compound parabolic concentrator, and a wavelength converting material, such as a phosphor. The concentrator element receives light from the LED and emits the light from an exit surface, which is smaller than the entrance surface. The wavelength converting material is, e.g., disposed over the exit surface. The radiance of the light emitting diode is preserved or increased despite the isotropic re-emitted light by the wavelength converting material. In one embodiment, the polarized light from a polarized LED is provided to a polarized optical system, such as a microdisplay. In another embodiment, the orthogonally polarized light from two polarized LEDs is combined, e.g., via a polarizing beamsplitter, and is provided to non-polarized optical system, such as a microdisplay. If desired, a concentrator element may be disposed between the beamsplitter and the microdisplay.
摘要:
A semiconductor light emitting device comprising a light emitting layer disposed between an n-type region and a p-type region is combined with a ceramic layer which is disposed in a path of light emitted by the light emitting layer. The ceramic layer is composed of or includes a wavelength converting material such as a phosphor. Luminescent ceramic layers according to embodiments of the invention may be more robust and less sensitive to temperature than prior art phosphor layers. In addition, luminescent ceramics may exhibit less scattering and may therefore increase the conversion efficiency over prior art phosphor layers.
摘要:
In a III-nitride light emitting device, a ternary or quaternary light emitting layer is configured to control the degree of phase separation. In some embodiments, the difference between the InN composition at any point in the light emitting layer and the average InN composition in the light emitting layer is less than 20%. In some embodiments, control of phase separation is accomplished by controlling the ratio of the lattice constant in a relaxed, free standing layer having the same composition as the light emitting layer to the lattice constant in a base region. For example, the ratio may be between about 1 and about 1.01.
摘要:
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;
摘要:
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.
摘要:
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. Thus, the chirped design of the multi-well active region increases the probability of radiative recombination of electrons and holes within the light emitting active layers of the active region, which results in an increased light output of the device. The multi-well active region of the device may be chirped with respect to light emitting active layers and/or barrier layers of the active region. The light emitting device may be a III-V material LED, a II-VI material LED, a polymer or organic LED, a laser diode or an optical amplifier.
摘要:
Light emitting devices having a vertical optical path, e.g. a vertical cavity surface emitting laser or a resonant cavity light emitting or detecting device, having high quality mirrors may be achieved using wafer bonding or metallic soldering techniques. The light emitting region interposes one or two reflector stacks containing dielectric distributed Bragg reflectors (DBRs). The dielectric DBRs may be deposited or attached to the light emitting device. A host substrate of GaP, GaAs, InP, or Si is attached to one of the dielectric DBRs. Electrical contacts are added to the light emitting device.
摘要:
A light emitting diode device has a bulk gallium and nitrogen containing substrate with an active region. The device has a lateral dimension and a thick vertical dimension such that the geometric aspect ratio forms a volumetric diode that delivers a nearly uniform current density across the range of the lateral dimension.