Cottrell Scholar Awards - 2017
Hot Electron Optoelectronics of Atomic Layer Heterostructures
Heat is the enemy in miniaturized electronics. In photovoltaics, for example, sunlight is converted directly to electricity, but some of the energy generated by a solar cell is also converted to heat, which, like the well-behaved electrons that produce a current, is also transferred along the molecular crystal lattice structure of the solar cell. The heat produced by overly excited electrons generally accumulates in unwanted places within a device, lessening its efficiency.
However, in extremely small devices, the heat carried by electrons may instead be utilized to increase device efficiency.
Nathaniel M. Gabor, physics, University of California, Riverside, has received a Cottrell Scholar Award from Research Corporation for Science Advancement to explore the heat and energy transfer qualities of new synthetic materials called transition metal dichalcogenides (TMDs). These are atomically thin semiconductors in which a metal atom and chalcogen atom are sandwiched together. (A transition metal, such as molybdenum or tungsten, is so named because it occupies the middle portion of the Periodic Table of Elements; a chalcogen is a chemical element classified within the oxygen family in the Table of Elements -- including sulfur (S), selenium (Se), and tellurium (Te), among others.)
Specifically, Gabor’s research involves combining TMDs into new “heterostructures” that include additional semiconductor materials such as graphene. (A heterostucture in this instance is an arrangement of atoms or molecules that restricts the movements of charge-carrying electrons, creating discrete energy levels and greater energy densities than traditional semiconductors.)
“These materials can be mechanically assembled to form heterostructures whose properties are not simply the sum of the constituent materials,” Gabor notes. “The new physics that emerges in these synthetic materials is still largely unresolved, owing to the burden of exhaustive comprehensive characterization and the need for new physical descriptions.”
If successful, the work could lead to greater efficiencies in photovoltaic panels and other electronic devices.
There is also an education component to the Cottrell Scholar Award. Gabor intends to use some of the funding to design instructional material introducing the growing importance of Data Science methods in fundamental research and applied science.
“Data Science, which incorporates ideas and techniques from a vast set of disciplines, is one of the fastest growing fields in both fundamental and applied science, and will employ a significant fraction of young, promising scientists in the near future,” he said.