Quantum-dots are tiny crystals of semiconductors just a few nanometres wide. Due to their unique ability to interact with light, they have the potential to significantly increase the efficiency and lower the price of photovoltaic cells.
Currently, the most efficient photovoltaic cells are made out of crystalline silicon. In silicon, one photon of light frees one electron from its atomic orbit. In quantum-dots made out of particular materials, up to seven electrons are freed per photon when exposed to high-energy ultraviolet light. Moreover, quantum-dots can be produced by simple chemical reactions, while crystalline silicon wafers are relatively expensive to manufacture.
To date, however, the extra-electron effect has been observed only in isolated quantum dots. In a working quantum-dot solar cell, most electrons are swallowed up before they leave the semiconductor dot. A commercial application of this technology is presumably still many years away.
However, the potential is already real enough for Moser Baer PhotoVoltaic Ltd to acquire a significant minority stake in Stion Corporation, one of the main R&D companies studying nanostructures technology. Moser Baer PhotoVoltaic Ltd is a wholly owned subsidiary of Moser Baer India Ltd.
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silicon nano structures for thermo-electricity
By Suresh Kumar / Published on Mon, 2008-01-21 9:32Usually we identify silicon with photo-electricity whether as PV or quantum dots [in combination or otherwise with other materials]
But some recent research suggests than nanostructures of silicon on thin wafer material can be used as thermo-electric materials to make use of heat from sun or other sources ,which will have much potential for green buildings in tropical countries. If you have more details on this or any related materials or processes please share.
thanks
Suresh Kumar
Scientish and Head, Policy and Planning
NIIST, Trivandrum, India
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