Optical Hyperdoping: Extending Silicon's Reach

Mark Winkler, Department of Physics, Harvard University

Friday, February 13, 2009

Spanos Auditorium

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This seminar is part of the Jones Seminars on Science, Technology, and Society series

Silicon is the world's most widely used semiconductor. As the building block of a photovoltaic cell, silicon offers a combination of stability, efficiency, and manufacturability currently unmatched by any other material. However, as an indirect absorber of light, thick layers of highly-pure, expensive material are required for efficient light absorption and charge collection. Furthermore, silicon does not absorb in the infrared, a spectral region that contains about a quarter of the sun's radiation. In this talk, I will discuss optical hyperdoping, a non-equilibrium laser-doping technique we have been developing for enhancing the optoelectronic properties of silicon. Our preliminary work has demonstrated this technique's promise for developing a new generation of silicon photovoltaics: enabling absorption in dramatically thinner layers and extending the useful spectral range of silicon into the infrared.

About the Speaker

Mark Winkler's research involves studying a new class of optical materials created via the intense interaction between matter and ultrashort pulses of light, as well as how such materials can be developed into new types of photovoltaics. In general, he is interested in the science of energy and the challenges of transitioning to a carbon-neutral energy economy. Mark is a fifth year Ph.D. student in Eric Mazur's group at Harvard University.