Research

Ferroelectric 2DMs for Neuromorphic Devices

Ferroelectric semiconductor 2D Materials are anticipated to realize neuromorphic computer architecture, where information is computed and stored in each of the constituting devices. Combining excellent electronic transport and room-temperature-stable excitonic emission of 2D materials will allow for ferroelectrically reconfigurable optoelectronic devices for neuromorphic applications.

Ferroelectric switching reconfigures the excitonic emission of a 2D-based emitter, and the drain current of 2D-based thin-film transistors.

ToC Image: Kim et al., (In Preparation)

Operando Functional Imaging

To fully comprehend and exploit the relationship between the material and device performance, material properties should be resolved on the nanoscale. 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.

ToC Image: Zhuang*, Kim* et al., PNAS (2023)
More reads: Zhu
et al., ACS Nano (2022); Kim et al., Adv. Mater., 34, 2205871 (2022)

Strain-engineering of 2D Materials

2D materials are atomically thin and can withstand extreme levels of mechanical strain without material failure, thus are an optimal system for strain engineering. Moreover, their layered structure allows for strong modulation of the heterostructures' optical and electronic properties via the application of out-of-plane strain.

Out-of-plane strain is shown to modulate band gaps and relative band offsets of 2D semiconductors. More intriguingly, charge transfer and energy transfer between the layers in heterobilayers can be engineered by controlled strain. Based on these findings, novel 2D device concepts have been developed to employ strain engineering in low-power electronics, strain sensors, and more.

ToC Image: Kim et al., ACS AMI, 14, 46841 (2022)
More reads
: Kim et al., 2D Mater., 5, 015008 (2018); Kim et al., J. Appl. Phys., 123, 115903 (2018); Pandey et al., Small, 12, 4063 (2016); Lu et al., Phys. Rev. B, 94 224512 (2016)