Thickness-Controlled Ferroelectric-to-Ionic Transport in CuCrP2S6 at Room Temperature
Abstract
Ambient-temperature coexistence of ferroelectricity, photoconductivity, and ionic transport in ultra-thin van der Waals (vdW) compound CuCrP2S6 (CCPS) offers significant potential for multifunctional electronic, photonic, and neuromorphic applications. However, ferroelectricity and ionic transport can become antagonistic when sharing a common atomic origin, like the copper ions in CCPS. We address this fundamental dichotomy by systematically investigating the thickness-dependent evolution of ferroelectricity, ionic migration, and memristive behavior in CCPS diodes via electrostatic and photo-assisted interfacial band tuning. Using piezoresponse, Kelvin probe, and conductive atomic force microscopy, alongside photoexcited transport measurements, we identify distinct thickness regimes. CCPS flakes thinner than ~ 40 nm exhibit robust, reversible ferroelectric (FE) switching. Conversely, thicker samples display suppressed switchable polarization, with electrical conduction dominated by Cu+ migration, filamentary memristive switching, and rectification reversal. Optical illumination further enhances ionic mobility via photogenerated carriers, driving photo-assisted ionic transport in non-FE flakes and a coupled photoferroionic response in FE flakes. These findings clarify how ferroelectricity fundamentally alters ionic transport dynamics in vdW ferroionic systems.
Related
- Non-Uniform Quantum Well and Barrier Thickness Engineering for Robust Ultra-High TER and Low RA Ferroelectric Tunnel Junctions
- Reconfigurable Ferroelectric‐Like Two‐Dimensional Electron Gas at Room Temperature
- Holonomy Analysis of Optical-polarization Temperature Trajectories in Stress-induced Ferroelectric SrTiO3
- Room-temperature ferroelectric p-wave magnet
- Pulsed Laser Deposition of Ferroelectric SrTiO3 Shells Enables Polarization-Controlled Charge Separation in TiO2 Photoanode
BibTeX
@misc{chatterjee2026thicknesscontrolled,
title = {{Thickness-Controlled Ferroelectric-to-Ionic Transport in CuCrP2S6 at Room Temperature}},
author = {Subhashree Chatterjee and Abhishek Bajgain and Rabindra Basnet and Ramesh C. Budhani},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.02380},
eprint = {2610.02380},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.02380},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Thickness-Controlled Ferroelectric-to-Ionic Transport in CuCrP2S6 at Room Temperature
AU - Subhashree Chatterjee
AU - Abhishek Bajgain
AU - Rabindra Basnet
AU - Ramesh C. Budhani
PY - 2026
DA - 2026/10/01
PB - arXiv
DO - 10.48550/arxiv.2610.02380
UR - https://arxiv.org/abs/2610.02380
AB - Ambient-temperature coexistence of ferroelectricity, photoconductivity, and ionic transport in ultra-thin van der Waals (vdW) compound CuCrP2S6 (CCPS) offers significant potential for multifunctional electronic, photonic, and neuromorphic applications. However, ferroelectricity and ionic transport can become antagonistic when sharing a common atomic origin, like the copper ions in CCPS. We address this fundamental dichotomy by systematically investigating the thickness-dependent evolution of ferroelectricity, ionic migration, and memristive behavior in CCPS diodes via electrostatic and photo-assisted interfacial band tuning. Using piezoresponse, Kelvin probe, and conductive atomic force microscopy, alongside photoexcited transport measurements, we identify distinct thickness regimes. CCPS flakes thinner than ~ 40 nm exhibit robust, reversible ferroelectric (FE) switching. Conversely, thicker samples display suppressed switchable polarization, with electrical conduction dominated by Cu+ migration, filamentary memristive switching, and rectification reversal. Optical illumination further enhances ionic mobility via photogenerated carriers, driving photo-assisted ionic transport in non-FE flakes and a coupled photoferroionic response in FE flakes. These findings clarify how ferroelectricity fundamentally alters ionic transport dynamics in vdW ferroionic systems.
ER -