The Solid State Materials and Chemistry Program within the Division of Materials Research supports the activities of this CAREER award. The objectives of this work are to explore, understand, and apply high aspect ratio, nanostructured binary and ternary phosphide semiconductors as materials for solar energy capture, conversion, and storage. This work specifically targets the synthesis of diamond-like, earth-abundant phosphides such as GaP, BP, ZnSiP2, ZnGeP2, ZnSnP2, CdSiP2, CdGeP2, and CdSnP2, semiconductors which have been largely unexplored as photoelectrode materials in photoelectrochemical systems. This work will demonstrate that the perceived limitations commonly ascribed to all of these materials are extrinsic in nature and can be overcome by judicious design and tailoring of their morphologies. The operation of phosphide alloys for solar energy applications will be understood through individual nanowire measurements, steady-state photoelectrochemical measurements of ensemble films, and transient photoresponse measurements. These data will provide a more complete understanding of their optoelectronic properties when prepared as nanowires with high aspect ratios. This work will both demonstrate that nanostructured phosphide binary and ternary alloy semiconductors have the capacity to fill the existing materials gap currently inhibiting the construction of scalable, fuel-forming photoelectrochemical cells and that the development of these materials also affords the opportunity to explore alternative dye-sensitized photoelectrode designs.
NON-TECHNICAL SUMMARY:
The broad goals of this project are to develop phosphide materials and material interfaces that could be used in solar energy conversion/storage technologies that have the potential to profoundly influence energy usage and distribution at a global scale. The research will focus on a detailed analyses of the effect that the interplay between material composition and morphology has on the ability to capture, convert, and utilize solar energy. Postdoctoral fellows, graduate students, and undergraduate students involved in these activities will be trained and skilled in materials characterization techniques, semiconductor device physics, and surface analytical techniques directly relevant to the fields of energy conversion/storage. The project will also feature energy-themed outreach activities designed to seed new and long-term interactions between the Department of Chemistry at the University of Michigan and Detroit area middle school students. The goals of these activities for middle school students are to make the science behind the invention of cleaner, safer, and more affordable renewable energy technologies more real, tangible, and enticing and to highlight promising career options in energy sciences within the state of Michigan.
