- By:
- Checa Nualart, Marti ; Jin, Xin; Millan-Solsona, Ruben; Neumayer, Sabine M; Susner, Michael; McGuire, Michael A; O'Hara, Andrew; Gomila, Gabriel; Maksymovych, Petro ; Pantelides, Sokrates; Collins, Liam F
- Journal Name:
- ACS Nano
- Page Number:
- 15347-15357
- Volume:
- 16
- Issue Number:
- 9
- Publication Date:
- December 27, 2023
- View DOI Listing:
- https://doi.org/10.1021/acsnano.2c06992
Abstract
Van der Waals layered ferroelectrics, such as CuInP2S6 (CIPS), offer a versatile platform for miniaturization of ferroelectric device technologies. Control of the targeted composition and kinetics of CIPS synthesis enables the formation of stable self-assembled heterostructures of ferroelectric CIPS and nonferroelectric In4/3P2S6 (IPS). Here, we use quantitative scanning probe microscopy methods combined with density functional theory (DFT) to explore in detail the nanoscale variability in dynamic functional properties of the CIPS-IPS heterostructure. We report evidence of fast ionic transport which mediates an appreciable out-of-plane electromechanical response of the CIPS surface in the paraelectric phase. Further, we map the nanoscale dielectric and ionic conductivity properties as we thermally stimulate the ferroelectric-paraelectric phase transition, recovering the local dielectric behavior during this phase transition. Finally, aided by DFT, we reveal a substantial and tunable conductivity enhancement at the CIPS/IPS interface, indicating the possibility of engineering its interfacial properties for next generation device applications.
