Optical concentrators are used to focus sunlight onto a smaller area where a photovoltaic cell is located in order to reduce the total area (and cost) of PV cells. Concentrators often have problems assocated with higher temperatures and the need to be moved to track the movement of the sun. This technology utilizes double sided PVs and multiple optical elements as a concentrating system to avoid the need for a moving concentrator.
Todays integrated circuits often can include millions of integrated components and devices. However, for a given product, it sometimes is not possible to achieve on one chip all of the circuitry required. A major challenge then becomes the interconnection of the circuitry on mulitple chips or substrates while keeping the connection resistance low and path lengths short to minimize inductive and capacitive effects, permitting high speed operation. Thus, a structure and method of forming compact integrated circuit assemblies and interconnections is needed.
Solid state radiation detectors, such as neutron detectors and gamma ray detectors, have been proposed as alternatives to gas-tube based detectors. Radiation-detecting hetero-structures may be formed by using physical etching processes, such as reactive ion etching (RIE) to form trenches in a semiconductor substrate, followed by using chemical vapor deposition (CVD) to deposit radiation-detecting material within the formed trenches.
This technology relates to nanoparticles that are particularly beneficial in optical systems. The nanoparticles include phosphor-functionalized particles with an inorganic nanoparticle core, surface polymer brushes in the form of long and short-chain polymers bonded to the inorganic nanoparticle core, and organic phosphors bonded to the inorganic nanoparticle core or the short-chain polymers. Applications for this technology include LEDs, lighting devices, fixtures, efficient light conversion materials, etc.
The use of fillers in both thermoplastic and thermoset polymers has been common. The practice of filling polymers is motivated both by cost reduction and by the need to obtain altered or enhanced properties. Nanostructured dielectric materials have demonstrated advantages over micro-filled polymer dielectrics. However, this is a need to improve these nanocomposites such that they can be adapted for use in such situations as electrical insulation for low or medium voltage cables.
This invention is directed to a method and apparatus for growing a multi-component single crystal boules that provides high quality and growth rate by growing the crystal from a multi-component melt, such as a ternary, quaternary or higher order melt. In the past, only binary compounds such as GaAs) could be commercially produced by directional solidification from melts, while compounds with more than two components resulted in a high density of defects.
The subject invention relates to a method for making ternary and quaternary semiconductor materials. These materials are currently produced in the form of thin layers by non-equilibrium growth techniques (from diluted solutions and vapor phase) on binary substrates using buffer layers to relieve misfit related stresses at the epilayer-substrate interface. One disadvantage of epitaxial technology is its high cost. In addition, the buffer layer technology is not optimized for all systems, and often devices exhibit large leakage currents due to poor interfacial regions.
Conventional methods for fabricating silicon carbide thyristors and gate turn-off thyristors include utilizing an all-epitaxial growth technique to fabricate each layer of the device. This epitaxial growth involves doping the crystal during crystal growth. This method has been the only method used for silicon carbide (SiC) thyristor fabrication. This invention is a new method for forming one or more doped layers using ion-implantation in the fabrication of thyristors after the crystal structure has been formed.
The intelligent control of lighting has the potential to bring benefits in energy consumption, human comfort and well-being, and worker productivity. Existing systems have various drawbacks including: (1) they often only detect the presence of people, and not their number and spatial distribution in the room; and (2) they typically use cameras or other high resolution sensors, which create high computational loads for real time operation and may present significant privacy or security concerns.
Current DRAM chips can ensure error-free data storage (except for radiation-induced soft errors), which largely simplifies the overall computing system design. Each DRAM cell contains one transistor and one capacitor. Unfortunately, it becomes increasingly challenging to maintain the sufficiently large capacitance (hence error-free data storage). It has become clear that STT-RAM has the true potential to complement or even replace DRAM as the main memory in computing systems. However, STT-RAM cannot achieve comparable bit cost as DRAM.