Nanotechnology for Solar Energy

March 17, 2009 by Craig · Leave a Comment

We will create low-cost paint-on solar cells to convert the sun’s power efficiently into electrical energy. Our goal is to break the present-day compromise between high efficiency and low cost in solar cells. We will work with colloidal quantum dots – semiconductor particles a few nanometers in diameter. These particles can be sprayed from the solution phase onto large, flexible substrates. Quantum dots also represent a highly tunable materials system: their bandgap is determined not only by the choice of semiconductor material used, but also by the size of the particles.

Any solar architecture that seeks to achieve ultra-high power conversion efficiencies must efficiently harvest the considerable energy of high-energy (blue) photons from the sun, and yet absorb low-energy (infrared) photons as well. Our first architecture will be based on multijunction devices: layers of different-bandgap photovoltaic cells stacked atop one another. The power from each layer will be added together either within the device or through an external circuit.
We will also pursue the realization of high-efficiency solar cells based on new classes of colloidal quantum dots. Successful optoelectronic devices based on this class of materials have, until now, included heavy metals such as lead or cadmium as constituent materials. We will optimize the properties of colloidal quantum dots that do not contain heavy metals, showing that these can be transformed into efficient solar energy harvesting devices.

We are tackling a challenge that is innately interdisciplinary. It spans materials chemistry, device fabrication, device optimization, careful optoelectronic characterization, and even ultrafast spectroscopic investigation. The research project will dovetail with KAUST’s Solar Energy Research Center, with planned exchanges of personnel, know-how, and experimental capacity between the KAUST and University of Toronto-based collaborating teams.

Dr. Edward Hartley Sargent, KAUST Investigator, is a professor and Canada Research Chair in Nanotechnology at the University of Toronto in Canada. Dr. Sargent is a world-renowned scientist who was named “one of the world’s top young innovators” by Technology Review (an MIT publication). He was also named to the Scientific American 50 for his achievements. In 2002, he won the Outstanding Engineer Award of the Institute of Electrical and Electronics Engineers of Canada. He is author of the book The Dance of Molecules: How Nanotechnology is Changing Our Lives.

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