Oct 12 2011
The Materials Research Society (MRS) has named Alex Zunger, professor at the University of Colorado, Boulder, to receive the inaugural Materials Theory Award for his "development of the Inverse Band Structure approach to materials by design and the foundational developments of methods of First-Principles theory of solids, leading to innovative and transformative studies of renewable-energy materials and nanostructures."
Zunger will receive his award at the 2011 MRS Fall Meeting on Wednesday, November 30, at 6:30 p.m. in the Grand Ballroom of the Sheraton Boston Hotel. The Materials Theory Award, endowed by Toh-Ming Lu and Gwo-Ching Wang, recognizes exceptional advances made by materials theory to the fundamental understanding of the structure and behavior of materials.
Zunger's fundamental work includes the fifth-most-cited paper in the 110-year history of Physical Review (out of over 350,000 articles published in the journal). He is also the recipient of the John Bardeen Award of the Minerals, Metals & Materials Society (TMS), the Rahman Award of the American Physical Society (APS), the Tomassoni Physics Prize and Science Medal of the Scola Romana di Physica in Italy and the Guttenberg Award of Science of Germany.
Zunger has made seminal contributions as a theorist working in the area of condensed matter and materials physics. He made foundational contributions to the development of the theory methodologies that enabled predicting a wide range of the properties of solids even before they were measured.
Such developments include the earliest first-principles pseudopotentials for greatly simplifying theory of many-electron systems, the momentum-space total energy approach for predicting the ground-state properties of solids, and the development of exchange-and-correlation functions for describing the fundamental electron-electron interactions in density-functional theory. His theoretical work on semiconductor alloys, complex photovoltaic semiconductors and nanostructures were contributions at the forefront of these fields.
His recent work is motivated by the goal to predict structural arrangements to design materials with desirable, "target" electronic properties. Prior to Zunger's proposal of an "inverse approach," the standard protocol was to first state the underlying structure of a solid or molecule (e.g., its symmetry, or structure type), then predict the system's properties (e.g., optical, mechanical, electric, magnetic) through quantum calculations. However, this approach did not reveal how the atomic structure should be changed to achieve a certain target property.
Zunger's idea was to start by articulating the material property desired for a particular technology (e.g., optical, mechanical, electric, magnetic) and then calculate the structure that would have the target property. Together with his collaborators at the National Renewable Energy Laboratory (NREL), he showed how one could predict (i) "nanostructures by design," as well as (ii) "magnetism by design," or even (iii) "impurities by design."
For example, (i) he asked the question, "If you had any amount of gallium arsenide (GaAs) 'planes' and aluminum arsenide (AlAs) 'planes,' how would you stack them (and in what direction) so that the ensuing structure has the largest possible band gap (i.e., shortest-wavelength absorption)?" Similarly, he asked, "Could you combine silicon and germanium-two fundamental semiconductor materials which do not absorb much light because of 'forbidden optical transitions'-so as to create a nanostructure that strongly absorbs light? Or, (ii) if you could place the magnetic atom of manganese (Mn) at any location within the non-magnetic crystal of GaAs, where would you put them to get the highest possible ferromagnetism (measured by a high 'Curie temperature'). Similarly, (iii) what configuration should nitrogen impurities take up in a simple semiconductor such as gallium phosphide (GaP) to create the most optically-active 'impurity band' inside the band gap?" Answers were obtained by combining biologically-inspired "genetic algorithms" (mimicking Darwinian evolution) with quantum-mechanical calculations of material properties. Such a strategy enables finding the right answer, out of an astronomically large number of possibilities, by actually trying only a tiny fraction of the possibilities.
Zunger's work now forms the basis for an office of science "Energy Frontier Research Center on Inverse Design," combining his theoretical work with the experimental work of groups at (NREL), Northwestern University, Stanford SLAC National Accelerator Laboratory and Oregon State University, who are realizing some of these target structures.
Zunger received a PhD degree from Tel Aviv University, Israel. He held postdoctoral research positions at Northwestern University and University of California, Berkeley. At NREL, he established the Solid State Theory group where he has mentored over 75 postdoctoral fellows and published over 600 papers in refereed journals, including over 150 in high-impact Physical Review Letters and Rapid Communications. The impact of his work is partially reflected by an "h factor" in the mid-nineties. He is a fellow of the American Physical Society.