This last December, chemistry researchers from the Neilson Group were selected for the American Chemical Society’s Open Access program Editors’ Choice in Chemistry of Materials. In Maughan and Neilson’s article titled “Anharmonicity and Octahedral Tilting in Hybrid Vacancy-Ordered Double Perovskites,” they describe the properties of two new materials discovered and synthesized by CSU undergraduates, (CH3NH3)2SnI6 and (CH(NH2)2)2SnI6. The team, led by CSU graduate student Annalise Maughan and Assistant Professor James Neilson used synchrotron X-ray scattering and characterization of the electronic behavior to understand how the atomic structure and its dynamics give rise to these paradigm-shifting properties for solar energy conversion. The work leveraged advanced quantum chemical theory-based calculations performed by collaborators at University College London (Dr. David Scanlon and Alex Ganose) to arrive at these conclusions. This research is supported by a grant funded by the United States Department of Energy, Office of Science.
Undergraduates are essential for new insights!
This publication showcases work by two CSU undergraduate researchers, Juliette Granger (CSU Chemistry alumnus 2016) and Andrew Candia (current CSU student). Granger and Candia were trained by CSU graduate student Annalise Maughan to use a combination of chemical routes to synthesize and then characterize these new materials. As these were new materials, the team had to develop their own approaches, bringing together solid-state chemistry, wet-chemistry, and mechano-chemistry to synthesize pure-phase products. Because of the excellent staffing and equipment in the Central Instrument Facility, both Granger and Candia were individually trained to perform their own characterization of their reaction products; this independence enabled them to formulate and test their own hypotheses to deliver the intellectual insights needed for the project’s success.
Front cover art selection:
Maughan stated “the selection of their article for ACS Editors’ Choice and the cover art for this issue of Chemistry of Materials is an absolute honor. This work encompasses several years of uncharted synthesis, challenging measurements, and complex data analysis, and it is so rewarding to have our work recognized in this highly active area of photovoltaics and perovskite halide research. In our cover art, we show an artist’s representation of the anharmonic, dynamic nature of the structure of (CH3NH3)2SnI6 which plays a critical role in the electronic properties of these materials.”
About their research:
In 2012, photovoltaics research received a new hope for inexpensive, high-efficiency solar cells based upon a new set of materials: perovskite halides. These perovskites materials offer performance competitive with the industry standard silicon and CdTe solar cells, but with significantly easier synthesis chemistry. The discovery and rapid optimization of these materials has left unanswered questions about the relationships between chemistry, structure, and functional properties. Graduate Student Annalise Maughan and Assistant Professor Jamie Neilson aim to understand how chemistry influences materials properties such as electrical conductivity or light absorption in order to explain the advantageous performance of perovskites in solar photovoltaic devices.
Look for their article and cover art to be publicly available this February!