TY - JOUR
T1 - Unraveling Spatiotemporal Transient Dynamics at the Nanoscale via Wavelet Transform-Based Kelvin Probe Force Microscopy
AU - Biglarbeigi, Pardis
AU - Morelli, Alessio
AU - Pauly, Serene
AU - Yu, Zidong
AU - Jiang, Wenjun
AU - Sharma, Surbhi
AU - Finlay, Dewar
AU - Kumar, Amit
AU - Soin, Navneet
AU - Payam, Amir Farokh
PY - 2023/11/14
Y1 - 2023/11/14
N2 - Mechanistic probing of surface potential changes arising from dynamic charge transport is the key to understanding and engineering increasingly complex nanoscale materials and devices. Spatiotemporal averaging in conventional heterodyne detection-based Kelvin probe force microscopy (KPFM) inherently limits its time resolution, causing an irretrievable loss of transient response and higher-order harmonics. Addressing this, we report a wavelet transform (WT)-based methodology capable of quantifying the sub-ms charge dynamics and probing the elusive transient response. The feedback-free, open-loop wavelet transform KPFM (OL-WT-KPFM) technique harnesses the WT’s ability to simultaneously extract spatial and temporal information from the photodetector signal to provide a dynamic mapping of surface potential, capacitance gradient, and dielectric constant at a temporal resolution 3 orders of magnitude higher than the lock-in time constant. We further demonstrate the method’s applicability to explore the surface-photovoltage-induced sub-ms hole-diffusion transient in bismuth oxyiodide semiconductor. The OL-WT-KPFM concept is readily applicable to commercial systems and can provide the underlying basis for the real-time analysis of transient electronic and electrochemical properties.
AB - Mechanistic probing of surface potential changes arising from dynamic charge transport is the key to understanding and engineering increasingly complex nanoscale materials and devices. Spatiotemporal averaging in conventional heterodyne detection-based Kelvin probe force microscopy (KPFM) inherently limits its time resolution, causing an irretrievable loss of transient response and higher-order harmonics. Addressing this, we report a wavelet transform (WT)-based methodology capable of quantifying the sub-ms charge dynamics and probing the elusive transient response. The feedback-free, open-loop wavelet transform KPFM (OL-WT-KPFM) technique harnesses the WT’s ability to simultaneously extract spatial and temporal information from the photodetector signal to provide a dynamic mapping of surface potential, capacitance gradient, and dielectric constant at a temporal resolution 3 orders of magnitude higher than the lock-in time constant. We further demonstrate the method’s applicability to explore the surface-photovoltage-induced sub-ms hole-diffusion transient in bismuth oxyiodide semiconductor. The OL-WT-KPFM concept is readily applicable to commercial systems and can provide the underlying basis for the real-time analysis of transient electronic and electrochemical properties.
KW - Kelvin probe force microscopy (KPFM)
KW - time-resolved KPFM (tr-KPFM)
KW - wavelet transforms
KW - surface photovoltage
KW - transient quantification
UR - http://www.scopus.com/inward/record.url?scp=85177102777&partnerID=8YFLogxK
U2 - 10.1021/acsnano.3c06488
DO - 10.1021/acsnano.3c06488
M3 - Article
C2 - 37877266
SN - 1936-0851
VL - 17
SP - 21506
EP - 21517
JO - ACS Nano
JF - ACS Nano
IS - 21
ER -