LED Lighting Half-Time Report
An Executive Roundtable Discussion With The Scientist Who Develop Them And The Companies That Sell Them
February 9, 2010 | 5:30pm | Corwin Pavilion, UCSB 
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Photovoltaic (PV) technology is currently enjoying substantial growth and investment, owing to worldwide sensitivity to energy security and the importance of renewable energy as a means to mitigate carbon emissions. This talk will describe approaches to control of light-matter interactions leading to enhanced absorption in solar photovoltaic structures. Conventionally, it is thought that semiconductor photovoltaic absorbers should have a physical thickness comparable to the ‘optical thickness’ to enable nearly complete light absorption and photocarrier current collection.

A number of important breakthroughs in the past decade have focused attention on Si as a photonic platform. We review  recent progress in this field, focusing on efforts to make lasers on or in silicon and on silicon photonic integrated circuits. The impact active silicon photonic integrated circuits could have on telecommunications and on silicon electronics is presented.

Scientific and technical computing is a major element in the energy consumption and carbon emissions of universities and research organisations. Europe’s largest high performance computing (HPC) based research centre has an energy bill approaching $100 million annually. And HPC was found to be 14% of the almost $2 million per annum computing-related electricity bills in a middle-tier, mid-size, UK university, with a similar amount associated with science related conventional computing.

Micron-scale photonic devices integrated with standard CMOS processes have the potential to dramatically increase system bandwidths, performance, and configuration flexibility while reducing system power. Small devices have many advantages: reduced power, increased density, and increased speed. By integrating many thousands of these devices on a chip, photonics could potentially be used for most high-speed off-chip and global on-chip communication.  Integrated photonics has many advantages at the board and rack scale as well.

Energy consumption in our society is increasing rapidly. A significant fraction of the energy is lost in the form of heat. In this talk we introduce solid-state thermionic/ thermoelectric devices that allow direct conversion of heat into electricity. Novel metal-semiconductor nanocomposites are developed where the heat and charge transport are modified at the atomic level. Theory and experiment are compared for the case of rare-earth nanoparticles in a semiconductor matrix as well as in nitride metal/semiconductor multilayer films. High thermoelectric figure-of-merit >1 is achieved.

We currently are seeing an unprecedented global effort to reduce carbon dioxide in our atmosphere and oceans and combat global warming. Even in these times of significant change, many don’t truly understand the sources of their energy or the environmental and economic benefits (and downsides) of the alternatives. Coal, for example, is a vital source of energy for the world’s electricity (50% in America and 70% in China), yet it contributes 40% of the world’s carbon dioxide.

Thermoelectrics are being used for applications such as heating and cooling car seats. New applications include personal air conditioning, improving the gas mileage of automobiles, and solar thermal power generation. Learn about some of these new applications, and new materials being designed to achieve better efficiency in these applications. Nanoparticles in materials are being used to improve the performance of thermoelectrics.

The design and synthesis of organic molecules and polymers for applications in organic light emitting diodes and organic photovoltaics will be presented.