Research
Our group focuses on materials modeling and simulation by using and developing computational approaches that leverage the accuracy of quantum-mechanics-based atomistic simulation and efficiency of data-driven/physics-based machine learning for the theory and design of advanced materials for next-generation electronics and optoelectronics.
Materials for non-von Neumann Computing
Phase change materials (PCMs), which can be reversibly switched between their high-conductive crystalline phase and low-conductive amorphous phase within nanoseconds, are promising for high-density data storage, in-memory and neuromorphic computing. We use atomistic simulation combined with machine learning to explore the structure-property relationship for design of novel PCMs, and for multi-scale materials and device simulations.
Moiré Materials
Twisted layered 2D materials form moiré potential profile that can strongly modulate the behavior of electrons and excitons, leading to emergent quantum phenomena. We develop high-performance computational framework to understand and predict the moiré potentials, electron correlations, ferroelectricity and multiferroic order in moiré materials.
Near- and Far-Field Theory for Tuning 2D Material Properties
Properties of two-dimensional (2D) materials can be strongly impacted by both near-field and far-field electrostatic effects, which are largely tunable for organic molecules. We derive electrostatic models and analytical theory for those effects from self-assembled molecular layers and their impacts on the electronic and optoelectronic properties of 2D materials.
Interface Physics for Van der Waals Heterostructures
Low-dimensional materials and their heterostructures are strongly tunable by quantum confinement, interface electronic coupling and heterogeneous dielectric screening. This large tunability leads to emergent properties when two materials are combined to form heterostructures, opening novel design strategies for electronic and optoelectronic applications. We develop computational approaches and theories for describing, understanding and tuning emergent properties of van der Waals heterostructures.
S. Amsterdam, et al., J. Am. Chem. Soc. 143, 41 (2021).
Q. Zhou, et al., APL Materials, 9, 12 (2021).
Q. Zhou, et al. J. Phys. Chem. A., 125, 19 (2021).
S. Li, et al. ACS Nano. 14, 3 (2020).
S. Amsterdam, et al., ACS Nano, 13, 4 (2019).
J. Olding, et al., ACS Appl. Mater. Interfaces, 11, 43 (2019).
Thermionic Electron Emitting Materials and Devices
Thermionic electron emitting cathodes are used in various electron devices for energy conversion, signal and power magnification. Thermionic electron emitting performance is highly dependent on the electronic and surface properties of the cathode materials. Surface chemistry and interface physics play important roles in controlling those properties.
M. Seif, Q. Zhou, et al. IEEE Trans. Electron Devices, 69, 7 (2022), 3513 - 3522.
M. Seif, Q. Zhou, et al. IEEE Trans. Electron Devices, 69, 7 (2022), 3523 - 3534.
Q. Zhou, et al., Appl. Surf. Sci., 458 (2018).