Inorganic Chemistry Seminar: Professor Thomas Kempa, Johns Hopkins University (Host: Matt Kanan)
About the Seminar
"Building the Building Blocks of Quantum Materials"
Quantum materials are poised to transform the development of next-generation sensors, analytical instruments, information processing systems, and energy conversion platforms. However, before realizing these lofty goals, researchers must first learn to harness the complex optical and magnetic states, non-trivial electronic correlations, and topological effects such materials support. Eliciting and controlling these desired properties will require low-dimensional crystals whose size, shape, structure, and composition can be tailored to atomic levels of precision. Chemistry will play a vital role in rational synthesis of these crystalline building blocks of quantum hardware. In this vein, my group has focused on tailoring two-dimensional (2D) materials to uncover and harness quantum phenomena. Through our work spanning the preparation of 2D atomic lattices and 2D molecular frameworks we have found that even subtle changes in the dimensionality and morphology of these materials yields substantial property changes. Notably, we can manipulate precisely the dimensionality of 2D transition-metal dichalcogenide crystals by growing these materials on chemically functionalized surfaces. The resulting nanoribbons emit light whose energy and profile show an unexpected progression as a function of crystal size. Seeking to expand the 2D materials landscape beyond atomic lattices, we have also prepared and examined new 2D molecular frameworks. A reversible 1D-to-2D phase switching can be induced in these frameworks with concomitant and substantial change in electronic transport. Our efforts underscore the importance of rational synthesis in building low-dimensional materials that enable new discoveries and advance the fields of optics, electronics, energy conversion, and quantum sensing.
About the Speaker
Thomas J. Kempa is an Assistant Professor of Chemistry and of Materials Science and Engineering at Johns Hopkins University. He holds a bachelor’s degree in chemistry from Boston College (2004) and spent 2 years as a post-graduate student at Imperial College London courtesy of a Marshall Scholarship. After returning to the United States, Tom pursued graduate studies in chemistry under the direction of Prof. Charles Lieber at Harvard University where he focused on the discovery and development of nanoscale materials for next-generation solar cells and photonic devices. After receiving his PhD in 2012, Tom conducted postdoctoral studies in the laboratory of Prof. Daniel Nocera, first at MIT and then at Harvard, and focused on harnessing electrochemical and hydrodynamic phenomena to form complex patterns of inorganic nanostructures. Over the course of his graduate and post-doctoral studies, Tom has received the MRS Graduate Student Award, the Dudley Herschbach Teaching Award, and the 2013 IUPAC Young Chemist Prize.
Professor Kempa’s research group develops new methods to prepare and study low-dimensional (low-D) inorganic crystals from nanoparticles (0D) to few-atom thick sheets (2D) whose exceptional properties render them intriguing platforms for optoelectronic, energy conversion, and quantum science studies. His group's expertise spans the areas of physical, inorganic, and materials chemistry. Professor Kempa is the recipient of numerous awards including an NSF CAREER Award, a DARPA Young Faculty Award, a Toshiba Distinguished Young Investigator Award, a Dreyfus Foundation Fellowship in Environmental Chemistry, and the Hopkins Discovery Award.