T. Dey, X. Lai, S. Manna, K. Patel, R. K. Patel, R. S. Bisht, Y. Zhou, S. Shah, E. Y. Andrei, S. Sankaranarayanan, D. Kuzum, C. Schuman and S. Ramanathan

February, 2025

ACS Nano

https://doi.org/10.1021/acsnano.4c11567

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Abstract

Ion drift in nanoscale electronically inhomogeneous semiconductors is among the most important mechanisms being studied for designing neuromorphic computing hardware. However, nondestructive imaging of the ion drift in operando devices directly responsible for multiresistance states and synaptic memory represents a formidable challenge. Here, we present Kelvin probe force microscopy imaging of hydrogen-doped perovskite nickelate device channels subject to high-speed electric field pulses to directly visualize proton distribution by monitoring surface potential changes spatially, which is also supported with finite element-based electric field distribution studies. First-principles calculations provide mechanistic insights into the origin of surface potential changes as a function of hydrogen donor doping that serves as the contrast mechanism. We demonstrate 128 (7-bit) nonvolatile conductance levels in such devices relevant to in-memory computing applications. The synaptic plasticity measurements are implemented in spiking neural networks and show promising results for classification (SciKit Learn’s Iris and Wine data sets) and control (OpenAI’s CartPole-v1 and BipedalWalker-v3) simulation tasks.

Citation Information

Text

author      T. Dey and X. Lai and S. Manna and K. Patel and R. K. Patel and 
            R. S. Bisht and Y. Zhou and S. Shah and E. Y. Andrei and 
            S. Sankaranarayanan and D. Kuzum and C. Schuman and S. Ramanathan
title       Kelvin Probe Force Microscopy Imaging of Plasticity in Hydrogenated Perovskite Nickelate Multilevel Neuromorphic Devices
journal     ACS Nano
volume      19
number      7
pages       6815-6825
year        2025
doi         10.1021/acsnano.4c11567
url         https://doi.org/10.1021/acsnano.4c11567

Bibtex

@ARTICLE{dlm:25:kpf,
    author = "T. Dey and X. Lai and S. Manna and K. Patel and R. K. Patel and 
                R. S. Bisht and Y. Zhou and S. Shah and E. Y. Andrei and 
                S. Sankaranarayanan and D. Kuzum and C. Schuman and S. Ramanathan",
    title = "Kelvin Probe Force Microscopy Imaging of Plasticity in Hydrogenated Perovskite Nickelate Multilevel Neuromorphic Devices",
    journal = "ACS Nano",
    volume = "19",
    number = "7",
    pages = "6815-6825",
    year = "2025",
    doi = "10.1021/acsnano.4c11567",
    url = "https://doi.org/10.1021/acsnano.4c11567"
}