The Straus Lab will focus on using atomically precise nanocrystals to build functional crystalline materials for optoelectronic, magnetic, quantum, and catalytic applications. Atomically precise nanocrystals are like conventional small molecules in that every nanocrystal of a given size and composition is identical, so they can crystallize into materials that exhibit long-range order, while retaining some of the size-tunability of conventional colloidal nanocrystals. They are sometimes referred to as superatoms because they can be used analogously to atoms to build functional crystalline materials with emergent properties different from those of isolated clusters with properties that cannot be accessed through conventional inorganic materials.
We will use open-shell superatoms (those with unpaired valence electrons) to build magnetic semiconductors, where both charge and spin can be manipulated. Magnetic semiconductors can therefore be used in classical and quantum devices where both computation and storage occur in a single device. The tunable properties of superatoms provide a viable platform to create materials with Curie temperatures (the temperature at which spins in a ferromagnet spontaneously order) greater than room temperature, potentially allowing superatomic magnetic semiconductors to power commercially-viable spintronic computers.
Most superconductors are extended inorganic metals or doped semiconductors. Some molecular solids also superconduct, such as Beechgard salts and fullerides. We will develop superatomic superconductors to explore the space between bulk inorganic and molecular superconductors. A material's superconducting transition temperature Tc is proportional to the density-of-states at the Fermi energy, so quantum confinement effects in superatomic superconductors may allow room-temperature superconductivity to be finally realized.
When most chemists think about chirality, chiral organic or organometallic molecules are what come to mind. In addition to molecules, crystalline materials can also be chiral. Chiral materials can be composed of chiral molecules, but extended inorganic materials (such as quartz) or molecular materials composed of achiral molecules can also be chiral, and both left- and right-handed crystals can form in a single growth. The forces that direct the handedness of these types of chiral materials remain mysterious.
We will develop methods to control the handedness of inorganic and molecular chiral materials so we can synthesize enantiomorphically pure crystals and thin films of inorganic and molecular chiral materials. We also plan to create enantiomorphically switchable chiral materials materials, which will be able to have their handedness be repeatedly and reversibly switched between their left- and right-handed enantiomorphs.
While we will develop these techniques on traditional molecular and inorganic materials, we will apply them to superatomic materials to harness properties not achievable with traditional materials.
These fundamental discoveries will enable the development of revolutionary chiral optoelectronic devices and stereoselective catalysis.