Related Basic Energy Sciences Project
Predicting the Electronic Properties of 3D, Million-Atom
Semiconductor Nanostructure Architectures
The past ~10 years have witnessed revolutionary breakthroughs both in synthesis of quantum dots
(leading to nearly monodispersed, defect-free nanostructures) and in characterization of such systems
revealing ultra narrow spectroscopic lines of ~1 meV width, exposing intriguing charging effects,
multiple exciton generation, fine-structure, quantum entanglement, multi-excitonic complexes and
more. These discoveries led to the invention of new technological applications including quantum
computing and ultra-high efficiency solar cells. The work in this project is based on two
realizations/observations: First, that the dots exhibiting clean and rich spectroscopic and transport
characteristics are rather big. Indeed, the phenomenology indicated above is exhibited only by the
well-passivated defect-free quantum dots containing at least few thousand atoms (colloidal) and even
a couple of million atoms (self assembled). Second, first-principles many-body computational
techniques based on current approaches (Quantum Monte-Carlo, GW, Bethe-Salpeter) are unlikely to
be adaptable to such large structures and, at the same time, the effective-mass based techniques are
too crude to provide insights on the many-body/atomistic phenomenology revealed by experiment.
Thus, this team has developed a set of methods that use an atomistic approach (unlike effective-mass
based techniques) and utilize single-particle + many body techniques that are readily scalable (unlike
Amcor BES) to ~10^3–10^6 atom nanostructures. A result of the team approach has led to significant improvements
in the algorithms developed initially.
Institutions Involved
- National Renewable Energy Laboratory - Alex Zunger (PI), A. Franceschetti, Gabriel Bester,
Wesley Jones, Kwiseon Kim
- University of Tennessee - Jack Dongarra
- Lawrence Berkeley National Laboratory - Lin-Wang Wang, Andrew Canning, Osni Marques
Principal Investigator
Alex Zunger
alex_zunger@nrel.gov
National Renewable Energy Laboratory
