Next Generation Photovoltaics
Nanostructured Materials for Photovoltaic Interdisciplinary Research Group Leader: Reuben Collins
CSM Faculty: Sumit Agarwal, Dick Ahrenkiel, Charles Durfee, Tom Furtak, Mark Lusk, Tim Ohno, Jeff Squier, Craig Taylor, Kim Williams, Zhigang Wu
NREL Staff: Matt Beard, Howard Branz, Alberto Franceschetti, Art Nozik, Pauls Stradins, Justin Johnson, Qi Wang, Dana Olson
Postdoctoral Fellow: Chito Kendrick
Center Graduate Fellows: Huashan Li, JJ Airuoyo, Matt Bergren, Thomas Brenner, Aaron Martinez, Bob Lochner, Elyse McEntee, Gang Chen, Jacob Bell, Tianyuan Guan, Grant Klafehn
The Nanostructured Materials for Photovoltaic Interdisciplinary Research Group (IRG) seeks new paradigms in photovoltaic (PV) energy collection using primarily silicon-based nanostructures. It explores the synthesis modeling and characterization of isolated Si nanostructures and nanostructures in novel matrices to create architectures where energy and charge transport are optimized allowing novel size dependent properties to be harnessed.
With the possible exception of silicon-based nanowire structures, fundamental studies of PV-related nano phenomena in Si-based systems have advanced much less than in other materials. A central reason for this is that II-VI and IV-VI nanoparticles have simple solution-based routes for the synthesis of high quality colloidal dot structures. There are many reasons, however, to emphasize Si nanostructures. In addition to the common arguments of abundance, low toxicity, and a history of manufacturing to borrow from, Si-based materials in combination with other column IV elements exhibit a rich phase space of alloys and core-shell structures which are much more accessible as nano-materials where strain can be more easily managed. Also, unlike II-VI’s, doping and transport are well understood for both n and p-type materials.
This IRG has developed new understanding of the role surface defects in Si dots play in oxidation, of the way in which quantum dot size can be used to reduce the sensitivity to oxidation while also improving energy collection, and of the important role the region between dots - the matrix or white space - plays in designing a quantum dot based PV material. By emphasizing, rather than ignoring, the matrix, new nano enabled paradigms for energy harvesting that extend from exciton transport to hot carrier transfer become possible.