Professor Aaron Fafarman received a five-year National Science Foundation Faculty Early Career Development grant (NSF-CAREER), supported by the Solid State and Materials Chemistry program in the Division of Materials Research, for his research that will fundamentally expand the palette of materials available for solar cells and other applications by rendering metastable structures stable. Metastable structures exist only temporarily before reverting to their "preferred" stable structure. In spite of this drawback there exist a vast number of metastable materials with otherwise ideal properties for a variety of technological applications. For example, among the diverse class of materials known as metal halide perovskites there exist metastable variants that combine ideal properties for efficient solar cells (over 23% efficient solar-to-electricity energy conversion) with extremely low-cost, scalable synthesis. This project will provide critical new avenues to exploiting these ideal characteristics in structures that have been newly rendered stable by the techniques proposed herein.
In this work, the hypothesis will be tested that when a piece of metastable material is made very small--one ten-thousandths of the thickness of a human hair--it will be possible to selectively enhance its stability. The tremendous social dividends of the low-cost solar cells that could result from this work include reduced anthropogenic emission of green-house gases, increased domestic energy security, a sustainable energy economy and growth of jobs in the development and manufacture of an important high-tech commodity. Undergraduate and graduate students will receive interdisciplinary training in chemistry, solid-state physics and electrical engineering tools and concepts, emerging with skills for a twenty first century manufacturing economy. As part of this work, local, public junior high students will get hands-on experience synthesizing solar energy conversion materials in a format designed to bolster their creation of a positive identity as practitioners of STEM.