Materials with different dimensionality exhibit various materials properties, such as dielectric screening, electronic band structure, interface states, and mechanical moduli. The hetero-interface between such dissimilar materials allows novel device behavior that is absent in either material, but only appears in the heterostructure forms.
The mixed-dimensional heterostructure research targets to engineer reconfigurable devices, which respond to external stimuli such as electric and magnetic field, mechanical strain, optical excitation, and chemical species.
(Jariwala et al., Nat. Mater., 16, 170 (2017))
In-Operando Functional Imaging
To fully comprehend and exploit the relationship between the material and device performance, material properties should be resolved on the nanoscale. In-operando functional imaging combines electrical transport measurements with scanning probe techniques to visualize the electronic and optical properties of nanostructured materials.
Kelvin Probe Force Microscopy (KPFM) can measure potential profiles of operating devices, providing a powerful tool to examine the carrier transport schemed in the contacts and junctions.
(Zhuang, Kim et al. (in review))
Strain-engineering 2D Materials
2D materials are atomically thin and can withstand an extreme level of strain without material failure, thus an optimal system for strain engineering. Also, its layered structure allows for the large modulation of out-of-plane bonds. This leads to immense modulation of electronic, optical, thermal, and topological properties.
Novel 2D device concepts have been developed to employ strain-engineering into low-power electronics, strain sensors, and more.
(Kim et al., 2D Mater., 5, 015008 (2018))