Visualization of Charge Migration in Conductive Polymers via Time-Resolved Electrostatic Force Microscopy

Kajimoto, Kentaro; Araki, Kento; Usami, Yuki; Ohoyama, Hiroshi; Matsumoto, Takuya

doi:10.1021/acs.jpca.9b12017

Cited by 13 publications

(6 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A real-time analysis method was recently demonstrated using EFM (Kajimoto et al 2020 ). In this study, the charge migration on a polymer film was confirmed on a micro-second time scale.…”

Section: Discussionmentioning

confidence: 99%

Advanced atomic force microscopy-based techniques for nanoscale characterization of switching devices for emerging neuromorphic applications

et al. 2021

View full text Add to dashboard Cite

Neuromorphic systems require integrated structures with high-density memory and selector devices to avoid interference and recognition errors between neighboring memory cells. To improve the performance of a selector device, it is important to understand the characteristics of the switching process. As changes by switching cycle occur at local nanoscale areas, a high-resolution analysis method is needed to investigate this phenomenon. Atomic force microscopy (AFM) is used to analyze the local changes because it offers nanoscale detection with high-resolution capabilities. This review introduces various types of AFM such as conductive AFM (C-AFM), electrostatic force microscopy (EFM), and Kelvin probe force microscopy (KPFM) to study switching behaviors.

show abstract

“…A real-time analysis method was recently demonstrated using EFM (Kajimoto et al 2020 ). In this study, the charge migration on a polymer film was confirmed on a micro-second time scale.…”

Section: Discussionmentioning

confidence: 99%

Advanced atomic force microscopy-based techniques for nanoscale characterization of switching devices for emerging neuromorphic applications

et al. 2021

View full text Add to dashboard Cite

show abstract

“…We previously reported that the polaron mobility in SPAN is 0.25 cm 2 V −1 s −1 ; therefore, the detected carrier mobility is lower than the polaron mobility. [ 37 ] This suggests that the carriers in this system have an ionic rather than polaronic character. The carrier mobility is consistent with previously reported values for the ionic mobility in conductive polymers (10 −3 –10 −5 cm 2 V −1 s −1 ).…”

Section: Resultsmentioning

confidence: 99%

In‐Materio Reservoir Computing in a Sulfonated Polyaniline Network

et al. 2021

Self Cite

View full text Add to dashboard Cite

A sulfonated polyaniline (SPAN) organic electrochemical network device (OEND) is fabricated using a simple drop‐casting method on multiple Au electrodes for use in reservoir computing (RC). The SPAN network has humidity‐dependent electrical properties. Under high humidity, the SPAN OEND exhibits mainly ionic conduction, including charging of an electric double layer and ionic diffusion. The nonlinearity and hysteresis of the current–voltage characteristics progressively increase with increasing humidity. The rich dynamic output behavior indicates wide variations for each electrode, which improves the RC performance because of the disordered network. For RC, waveform generation and short‐term memory tasks are realized by a linear combination of outputs. The waveform task accuracy and memory capacity calculated from a short‐term memory task reach 90% and 33.9, respectively. Improved spoken‐digit classification is realized with 60% accuracy by only 12 outputs, demonstrating that the SPAN OEND can manage time series dynamic data operation in RC owing to a combination of rich dynamic and nonlinear electronic properties. The results suggest that SPAN‐based electrochemical systems can be applied for material‐based computing, by exploiting their intrinsic physicochemical behavior.

show abstract

“…The inhomogeneity of surface photovoltage on Si wafer has been characterized by mapping minority carrier distribution length [39]. The time-resolved Kelvin probe force microscopy can be used to acquire the time-resolved information of surface potential and carrier lifetime [40,41]. Although the time-resolved imaging in an order of picoseconds is not achieved to measure the dynamic change of excited carriers, these techniques can be applied visualize the spatial resolution of dynamic change due to local carriers inside conductive polymers [41].…”

Section: Proposed Model Of Current Noise Generationmentioning

confidence: 99%

Local-field-induced current noise in shape-limited self-doped polyaniline

Bao¹,

Otsuka²,

Etoh³

et al. 2020

Nanotechnology

View full text Add to dashboard Cite

Electronic noise generators are an essential component of molecular neuromorphic devices. To realize molecular noise generators with a high degree of freedom for design and integration into molecular devices, the utilization of the local electric field for the modulation of electrical conduction via a shape-limited conductive polymer is one promising strategy. Herein, a molecular noise generator composed of thin self-doped polyaniline (SPAN) lines is reported. SPAN lines fabricated via fountain pen lithography on SiO 2 /Si substrates were found to generate current noise upon laser irradiation. This current noise exhibited white-noise-like power spectral density in the frequency range of 1-25 Hz and was independent of temperature. Multiple independent noise generation on the same substrate was also successfully demonstrated. The present results indicate that the noise generation mechanism involves the local modulation of hopping conduction via SPAN lines owing to the spatial proximity of the conduction path in the SPAN line to the surface photovoltage region of the SiO 2 /Si interface. This on-site random noise generation in shape-limited conductive polymers is expected to be beneficial for the realization of molecular neuromorphic devices.

show abstract

Visualization of Charge Migration in Conductive Polymers via Time-Resolved Electrostatic Force Microscopy

Cited by 13 publications

References 38 publications

Advanced atomic force microscopy-based techniques for nanoscale characterization of switching devices for emerging neuromorphic applications

Advanced atomic force microscopy-based techniques for nanoscale characterization of switching devices for emerging neuromorphic applications

In‐Materio Reservoir Computing in a Sulfonated Polyaniline Network

Local-field-induced current noise in shape-limited self-doped polyaniline

Contact Info

Product

Resources

About