High-Speed Sparse Scanning Kelvin Probe Force Microscopy

A technical paper titled “High-speed mapping of surface charge dynamics using sparse scanning Kelvin probe force microscopy” was published by researchers at Oak Ridge National Laboratory, (ORNL), Sungkyunkwan University, Case Western Reserve University, Flinders University, Bedford Park, and UNSW Sydney.

Abstract:

“Unraveling local dynamic charge processes is vital for progress in diverse fields, from microelectronics to energy storage. This relies on the ability to map charge carrier motion across multiple length- and timescales and understanding how these processes interact with the inherent material heterogeneities. Towards addressing this challenge, we introduce high-speed sparse scanning Kelvin probe force microscopy, which combines sparse scanning and image reconstruction. This approach is shown to enable sub-second imaging (>3 frames per second) of nanoscale charge dynamics, representing several orders of magnitude improvement over traditional Kelvin probe force microscopy imaging rates. Bridging this improved spatiotemporal resolution with macroscale device measurements, we successfully visualize electrochemically mediated diffusion of mobile surface ions on a LaAlO₃/SrTiO₃ planar device. Such processes are known to impact band-alignment and charge-transfer dynamics at these heterointerfaces. Furthermore, we monitor the diffusion of oxygen vacancies at the single grain level in polycrystalline TiO₂. Through temperature-dependent measurements, we identify a charge diffusion activation energy of 0.18 eV, in good agreement with previously reported values and confirmed by DFT calculations. Together, these findings highlight the effectiveness and versatility of our method in understanding ionic charge carrier motion in microelectronics or nanoscale material systems.”

Find the technical paper here. Published November 2023.

Checa, M., Fuhr, A.S., Sun, C. et al. High-speed mapping of surface charge dynamics using sparse scanning Kelvin probe force microscopy. Nat Commun 14, 7196 (2023). https://doi.org/10.1038/s41467-023-42583-x

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