Abstract: An epitaxial semiconductor structure includes an engineered substrate having a substrate coefficient of thermal expansion. The engineered substrate includes a polycrystalline ceramic core, a barrier layer encapsulating the polycrystalline ceramic core, a bonding layer coupled to the barrier layer, and a single crystalline layer coupled to the bonding layer. The epitaxial semiconductor structure also includes an epitaxial layer coupled to the single crystalline layer. The epitaxial layer is characterized by an epitaxial coefficient of thermal expansion substantially equal to the substrate coefficient of thermal expansion.

Abstract: A method for making a multilayered device on an engineered substrate having a substrate coefficient of thermal expansion includes growing a buffer layer on the engineered substrate, and growing a first epitaxial layer on the buffer layer. The first epitaxial layer is characterized by an epitaxial coefficient of thermal expansion substantially equal to the substrate coefficient of thermal expansion.

Abstract: A method for making a multilayered device on an engineered substrate having a substrate coefficient of thermal expansion includes growing a buffer layer on the engineered substrate, and growing a first epitaxial layer on the buffer layer. The first epitaxial layer is characterized by an epitaxial coefficient of thermal expansion substantially equal to the substrate coefficient of thermal expansion.

Abstract: A method for making a multilayered device on an engineered substrate having a substrate coefficient of thermal expansion includes growing a buffer layer on the engineered substrate, and growing a first epitaxial layer on the buffer layer. The first epitaxial layer is characterized by an epitaxial coefficient of thermal expansion substantially equal to the substrate coefficient of thermal expansion.

Abstract: A method for making a multilayered device on an engineered substrate having a substrate coefficient of thermal expansion includes growing a buffer layer on the engineered substrate, and growing a first epitaxial layer on the buffer layer. The first epitaxial layer is characterized by an epitaxial coefficient of thermal expansion substantially equal to the substrate coefficient of thermal expansion.

Abstract: A method for making a multilayered device on an engineered substrate having a substrate coefficient of thermal expansion includes growing a buffer layer on the engineered substrate, and growing a first epitaxial layer on the buffer layer. The first epitaxial layer is characterized by an epitaxial coefficient of thermal expansion substantially equal to the substrate coefficient of thermal expansion.

Abstract: A method for making a multilayered device on an engineered substrate having a substrate coefficient of thermal expansion includes growing a buffer layer on the engineered substrate, and growing a first epitaxial layer on the buffer layer. The first epitaxial layer is characterized by an epitaxial coefficient of thermal expansion substantially equal to the substrate coefficient of thermal expansion.

Abstract: A light-emitting device having an n-type semiconductor layer having a plurality of pits with planar regions between the pits, the pits being characterized by sidewalk that intersect the planar regions is disclosed. A plurality of alternating sub-layers of materials having different bandgaps is deposited on the n-type semiconductor layer. The sub-layers have thicknesses such that the sub-layers form an active layer in the planar regions between the pits and a super lattice on the sidewalls of the pits. A p-type semiconductor layer is deposited on the plurality of alternating sub-layers. One of the sub-layers includes an electron blocking layer. The electron blocking layer is characterized by a first thickness in the substantially planar regions and a second thickness in areas adjacent to the sidewalls of the pits, the second thickness being less than the first thickness.

Abstract: A laterally contacted blue LED device involves a PAN structure disposed over an insulating substrate. The substrate may be a sapphire substrate that has a template layer of GaN grown on it. The PAN structure includes an n-type GaN layer, a light-emitting active layer involving indium, and a p-type GaN layer. The n-type GaN layer has a thickness of at least 500 nm. A Low Resistance Layer (LRL) is disposed between the substrate and the PAN structure such that the LRL is in contact with the bottom of the n-layer. In one example, the LRL is an AlGaN/GaN superlattice structure whose sheet resistance is lower than the sheet resistance of the n-type GnA layer. The LRL reduces current crowding by conducting current laterally under the n-type GaN layer. The LRL reduces defect density by preventing dislocation threads in the underlying GaN template from extending up into the PAN structure.

Abstract: A laterally contacted blue LED device involves a PAN structure disposed over an insulating substrate. The substrate may be a sapphire substrate that has a template layer of GaN grown on it. The PAN structure includes an n-type GaN layer, a light-emitting active layer involving indium, and a p-type GaN layer. The n-type GaN layer has a thickness of at least 500 nm. A Low Resistance Layer (LRL) is disposed between the substrate and the PAN structure such that the LRL is in contact with the bottom of the n-layer. In one example, the LRL is an AlGaN/GaN superlattice structure whose sheet resistance is lower than the sheet resistance of the n-type GnA layer. The LRL reduces current crowding by conducting current laterally under the n-type GaN layer. The LRL reduces defect density by preventing dislocation threads in the underlying GaN template from extending up into the PAN structure.

Abstract: A light-emitting device capable of being powered by an AC power supply or an unregulated DC power supply is disclosed. The light-emitting device, in an aspect, is coupled to a controller, a light-emitting diode (“LED”) array, and a power supply, wherein the power supply can be an AC power source or an unregulated DC power source. While the power supply provides electrical power, the controller generates various LED control signals in response to power fluctuation of the electrical power. The LED array allows at least a portion of LEDs to be activated in accordance with the logic states of the LED control signals.

Abstract: A light emitting diode (“LED”) using an electrical conductive and optical transparent or semi-transparent layer to improve overall light output is disclosed. The device includes a first conductive layer, an active layer, a second conductive layer, an electrical conductive and optical transparent or semi-transparent layer, and electrodes. In one embodiment, the electrical conductive and optical transparent or semi-transparent layer has a first surface and a second surface, wherein the first surface is overlain the second conductive layer. The second surface includes a pattern which contains thick regions and thin regions for facilitating light passage.

Abstract: A light-emitting device capable of being powered by an AC power supply or an unregulated DC power supply is disclosed. The light-emitting device, in an aspect, is coupled to a controller, a light-emitting diode (“LED”) array, and a power supply, wherein the power supply can be an AC power source or an unregulated DC power source. While the power supply provides electrical power, the controller generates various LED control signals in response to power fluctuation of the electrical power. The LED array allows at least a portion of LEDs to be activated in accordance with the logic states of the LED control signals.

Abstract: A light-emitting device capable of being powered by an AC power supply or an unregulated DC power supply is disclosed. The light-emitting device, in an aspect, is coupled to a controller, a light-emitting diode (“LED”) array, and a power supply, wherein the power supply can be an AC power source or an unregulated DC power source. While the power supply provides electrical power, the controller generates various LED control signals in response to power fluctuation of the electrical power. The LED array allows at least a portion of LEDs to be activated in accordance with the logic states of the LED control signals.

Abstract: A light-emitting device capable of being powered by an AC power supply or an unregulated DC power supply is disclosed. The light-emitting device, in an aspect, is coupled to a controller, a light-emitting diode (“LED”) array, and a power supply, wherein the power supply can be an AC power source or an unregulated DC power source. While the power supply provides electrical power, the controller generates various LED control signals in response to power fluctuation of the electrical power. The LED array allows at least a portion of LEDs to be activated in accordance with the logic states of the LED control signals.

Abstract: A light-emitting device capable of being powered by an AC power supply or an unregulated DC power supply is disclosed. The light-emitting device, in an aspect, is coupled to a controller, a light-emitting diode (“LED”) array, and a power supply, wherein the power supply can be an AC power source or an unregulated DC power source. While the power supply provides electrical power, the controller generates various LED control signals in response to power fluctuation of the electrical power. The LED array allows at least a portion of LEDs to be activated in accordance with the logic states of the LED control signals.

Abstract: A light-emitting device capable of being powered by an AC power supply or an unregulated DC power supply is disclosed. The light-emitting device, in an aspect, is coupled to a controller, a light-emitting diode (“LED”) array, and a power supply, wherein the power supply can be an AC power source or an unregulated DC power source. While the power supply provides electrical power, the controller generates various LED control signals in response to power fluctuation of the electrical power. The LED array allows at least a portion of LEDs to be activated in accordance with the logic states of the LED control signals.

Abstract: A light emitting diode (“LED”) using an electrical conductive and optical transparent or semi-transparent layer to improve overall light output is disclosed. The device includes a first conductive layer, an active layer, a second conductive layer, an electrical conductive and optical transparent or semi-transparent layer, and electrodes. In one embodiment, the electrical conductive and optical transparent or semi-transparent layer has a first surface and a second surface, wherein the first surface is overlain the second conductive layer. The second surface includes a pattern which contains thick regions and thin regions for facilitating light passage.

Abstract: An electrically-pumped vertical-cavity surface-emitting laser (VCSEL) has multiple active regions. Embodiments of the invention provide an electrically-pumped VCSEL having a number of different p-i-n junction and electrode arrangements, which, in various embodiments, allow independent biasing of the multiple active regions, and, in other embodiments, allow simplified electrical connections.

Abstract: An electrically-pumped vertical-cavity surface-emitting laser (VCSEL) has multiple active regions. Embodiments of the invention provide an electrically-pumped VCSEL having a number of different p-i-n junction and electrode arrangements, which, in various embodiments, allow independent biasing of the multiple active regions, and, in other embodiments, allow simplified electrical connections.