(Funded by the U.S. Department of Energy, the National Science Foundation, and the National Aeronautics and Space Administration)
For the first time, researchers from the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab), Dartmouth College, Penn State, the University of California, Merced, and Université Catholique de Louvain in Belgium have demonstrated an approach that combines high-throughput computation and atomic-scale fabrication to engineer high-performance quantum defects. The researchers developed state-of-the-art, high-throughput computational methods to screen and accurately predict the properties of more than 750 defects in a two-dimensional material called tungsten disulfide. Then, working at the Molecular Foundry, a user facility at Berkeley Lab, the researchers developed and applied a technique that enables the creation of vacancies in tungsten disulfide and the insertion of cobalt atoms into these vacancies.

(Funded by the U.S. Department of Energy, U.S. Department of Defense, and the National Science Foundation)
Researchers from the U.S. Department of Energy’s SLAC National Accelerator Laboratory and Argonne National Laboratory; Stanford University; Harvard University; Columbia University; Florida State University; and the University of California, Los Angeles, have discovered new behavior in an 50-nanometer-thick two-dimensional material, which offers a promising approach to manipulating light that will be useful for devices that detect, control or emit light, collectively known as optoelectronic devices. Optoelectronic devices are used in light-emitting diodes (LEDs), optical fibers, and medical imaging. The researchers found that when oriented in a specific direction and subjected to linearly polarized terahertz radiation, an ultrathin film of tungsten ditelluride circularly polarizes the incoming light.

(Funded by the National Science Foundation and the U.S. Department of Energy)
Researchers from the U.S. Department of Energy’s Princeton Plasma Physics Laboratory and the University of Delaware have provided new insights into the variations that can occur in the atomic structure of two-dimensional materials called transition metal dichalcogenides (TMDs). The researchers found that one of the defects, which involves hydrogen, provides excess electrons. The other type of defect, called a chalcogen vacancy, is a missing atom of oxygen, sulfur, selenium, or tellurium. By shining light on the TMD, the researchers showed unexpected frequencies of light coming from the TMD, which could be explained by the movement of electrons related to the chalcogen vacancy.

(Funded by the National Science Foundation)
Researchers from the University of Illinois Urbana-Champaign have identified how gold nanoparticles transfer charge to a connecting semiconductor and quantified how much charge is transferred using different colors of light. The researchers theorized that by using light to excite collective electronic oscillations (also called a plasmon) in gold nanoparticles, they would get a boost in charge transfer to the semiconductor material. And their study confirmed their theory.

(Funded by the U.S. Department of Defense and the National Science Foundation)
Researchers from Purdue University and the University of Illinois Urbana-Champaign have created a process to develop ultrahigh-strength aluminum alloys that are suitable for additive manufacturing. The researchers produced the aluminum alloys by using several transition metals, including cobalt, iron, nickel and titanium. “These intermetallics have crystal structures with low symmetry and are known to be brittle at room temperature,” said Anyu Shang, one of the researchers involved in this study. “But our method forms the transitional metal elements into colonies of nanoscale, intermetallics lamellae that aggregate into fine rosettes. The nanolaminated rosettes can largely suppress the brittle nature of intermetallics.”