Materials Science Research Lecture

Abstract: Thin-film perovskite solar cells (PSCs), where the record efficiency has rocketed from under 4% to near 24% (comparable to silicon solar cells) in just nine years, offer unprecedented promise of low-cost, high-efficiency renewable electricity generation. Pb-containing organic-inorganic halide perovskite (OIHP) materials at the heart of PSCs have unique structures, which entail rotating organic cations inside inorganic cages, imparting them with desirable optical and electronic properties. To exploit these properties for PSCs application, the reliable deposition of high-quality OIHP thin films over large areas is critically important. The microstructures and grain-boundary networks in the resulting polycrystalline OIHP thin films are equally important as they control the PSC performance and stability. Fundamental phenomena pertaining to synthesis, crystallization, coarsening, microstructural evolution, and grain-boundary functionalization involved in the processing of OIHP thin films for PSCs will be discussed with specific examples. In addition, the discovery of new classes of Pb-free halide perovskites (all-inorganic, organic-inorganic, low-dimensional), together with the demonstration of viable PSCs based on these new materials, will be presented. Furthermore, the unique mechanical behavior of halide perovskites, and its implication on the reliability of PSCS, will be discussed. The overall goal of our research is to have deterministic control over the scalable processing of tailored halide perovskite thin films with desired compositions, phases, dimensionalities, microstructures, and grain-boundary networks for scalable, efficient, stable, and reliable PSCs of the future.

More about the Speaker:
Nitin P. Padture is the Otis E. Randall University Professor in the School of Engineering, and Director of the Institute for Molecular and Nanoscale Innovation, at Brown University. Previously, he was College of Engineering Distinguished Professor and founding Director of the NSF-funded MRSEC at the Ohio State University. Padture's research and teaching interests are in the broad areas of synthesis/processing, characterization, and properties/performance of advanced ceramics and nanomaterials used in applications ranging from jet engines to solar cells. He has over 210 publications to his credit, which have been cited widely, and he has presented over 210 invited/keynote/plenary talks in the US and abroad. A Fellow of the American Ceramic Society, Padture has received that society's Roland B. Snow, Robert L. Coble, and Richard M. Fulrath awards.  He is also a recipient of the U.S. Office of Naval Research Young Investigator Award, and a Fellow of the American Association for the Advancement of Science. Recently, he was honored by his undergraduate alma mater, Indian Institute of Technology (Bombay), with the Distinguished Alumnus Award. Padture is Editor of the international journals Acta Materialia and Scripta Materialia.