Layered hybrid metal-organic chalcogenolates (MOChas) present a versatile platform for exploring and engineering exceptional light-matter interactions, offering opportunities to design materials for advanced photonic and quantum technologies. This presentation will highlight our synthetic efforts to expand the library of MOChas, focusing on the development of 50 structurally diverse systems.
Compositionally complex and high-entropy perovskite oxides provide a unique platform for combining a vast chemical design space with the atomic-scale structural control of epitaxy. A central question is how the chemical disorder intrinsic to high-entropy materials interacts with the structural order imposed by epitaxial strain, interfaces, and nonequilibrium growth. Using B-site high-entropy La(Cr0.2Mn0.2Fe0.2Co0.2Ni0.2)O3 as a model system, we show that nominally equivalent transition-metal cations respond very differently to charge and oxygen chemical potential during PLD growth.
Two-dimensional (2D) halide perovskites represent a structurally extensible class of hybrid semiconductors with growing importance in optoelectronic research. Compared with their three-dimensional counterparts, 2D perovskites offer enhanced compositional and structural flexibility arising from reduced constraints on organic ligands, enabling molecular-level design of structure and function. In this talk, I will examine recent advances in 2D perovskites from the perspective of organic ligand design.
Magnesium diboride (MgB₂), a compound known since the 1950s, was unexpectedly discovered to be a superconductor with a transition temperature (Tc) of 39 K in 2001. This discovery sparked tremendous excitement in the superconductivity community and led to a rapid understanding of its fundamental properties, including its conventional BCS superconductivity with two weakly coupled electronic bands and two distinct superconducting energy gaps. The extreme volatility of magnesium strongly constrains the growth of MgB₂ single crystals and thin films.
Advances in ultraclean materials with very long electron mean-free paths, including GaAs/AlGaAs heterostructures and graphene, have opened new opportunities to study electronic transport beyond the conventional Ohmic regime. We experimentally investigate transport in 2D GaAs/AlGaAs electron systems, with mean-free paths 100 micron or longer at cryogenic temperatures, across ballistic, hydrodynamic and diffusive regimes using mesoscopic nonlocal device geometries.
Currently, 70% of all electrical power consumed is routed through power electronics and this fraction is set to increase even faster with further addition of renewable sources to the grid and electrification of transportation. A significant reduction in size, weight, and power loss (SWaP) of power electronics will revolutionize the way the electric grid operates. The lion’s share of power electronics is based on silicon, with a bandgap of 1.1 eV. A significant reduction in SWaP is possible by migrating to semiconductors with wider bandgaps than silicon.
The next generation of polymeric materials will need features typically associated with biological systems: programmable material properties and chemical composition, self-healing and self-regenerating capabilities, and compatibility with sustainable and scalable manufacturing practices. While engineering synthetic materials with such capacities is often challenging, these properties are inherent to biological materials, including biofilms, mycelium, and lichen.
Materials behavior often begins at the atomic scale, making the understanding of how atomic systems behave of vital importance. Atomistic simulation techniques such as molecular dynamics and density functional theory have become instrumental in quantifying how the properties of atomic-level materials systems propagate to larger length and time scales and dictate observed materials behavior.
Moiré superlattices are formed when two van der Waals layers are stacked vertically with a controlled twist angle. Transition metal dichalcogenides (TMDs) are semiconductor building blocks with highly tunable optical properties. After reviewing some early studies, I will discuss the limitations of TMD-based moiré superlattices and propose twisted hBN substrates as a new approach to expand the strategy of moiré engineering to a broader range of photonic materials.
Quantum computing is a transformative technology that will change the world by quickly solving impossible problems, but its fundamental unit of information, the qubit, is nearly impossible to fabricate especially en masse with full functionality. Single crystal defects form the basis for solid-state qubits; they are materials, and their information is physical in nature requiring extreme precision in fabrication. This presentation introduce past fs work fabricating single defects in SiC and then it will expand on our very successful preliminary demonstration showing that a singl
