Abstract
Nanoscale ferroelectric 2D materials offer the opportunity to investigate curvature and strain effects on materials functionalities. Among these, CuInP2S6 (CIPS) has attracted tremendous research interest in recent years due to combination of room temperature ferroelectricity, scalability to a few layers thickness, and ferrielectric properties due to coexistence of 2 polar sublattices. Here, we explore the local curvature and strain effect on polarization in CIPS via piezoresponse force microscopy and spectroscopy. To explain the observed behaviors and decouple the curvature and strain effects in 2D CIPS, we introduce the finite element Landau-Ginzburg-Devonshire model, revealing strong changes in hysteresis characteristics in regions subjected to tensile and compressive strain. The piezoresponse force microscopy (PFM) results show that bending induces ferrielectric domains in CIPS, and the polarization-voltage hysteresis loops differ in bending and nonbending regions. These studies offer insights into the fabrication of curvature-engineered nanoelectronic devices.
| Original language | English |
|---|---|
| Pages (from-to) | 22004-22014 |
| Number of pages | 11 |
| Journal | ACS Nano |
| Volume | 17 |
| Issue number | 21 |
| DOIs | |
| State | Published - Nov 14 2023 |
Funding
This effort (materials synthesis, PFM measurements) was supported as part of the center for 3D Ferroelectric Microelectronics (3DFeM), an Energy Frontier Research Center funded by the U.S. Department of Energy (DOE), Office of Science, Basic Energy Sciences under Award Number DE-SC0021118. The research (PFM measurements) was performed and partially supported at Oak Ridge National Laboratory’s Center for Nanophase Materials Sciences (CNMS), a U.S. Department of Energy, Office of Science User Facility, under user proposal CNMS2023-A-01858. The growth of single crystals of CIPS used in this work was supported by the National Science Foundation through the Penn State 2D Crystal Consortium-Materials Innovation Platform (2DCC-MIP) under NSF cooperative agreement DMR-1539916, and DMR-2039351. A.N.M. acknowledges support from the National Research Fund of Ukraine (project “Low-dimensional graphene-like transition metal dichalcogenides with controllable polar and electronic properties for advanced nanoelectronics and biomedical applications”, grant application 2020.02/0027). E.A.E. acknowledges support from the National Academy of Sciences of Ukraine.
Keywords
- 2D materials
- CuInPS
- curvature
- ferroelectric
- flexoelectric
- piezoresponse force microscopy
- strain