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Updated: Jun 17, 2026
Probe Type II Band Alignment in One-Dimensional Van Der Waals Heterostructures Using First-Principles Calculations
Published on: October 12, 2019
Ferroionic heterostructures with reconfigurable free-energy surface and band alignment across CuInP2S6 van der Waals
Hejin Yan1, Bowen Wang1, Gian-Marco Rignanese2
1Institute of Applied Physics and Materials Engineering, University of Macau, Taipa, Macau, 999078, China. yongqingcai@um.edu.mo.
Abstract:
Two-dimensional ferroelectric semiconductors with nonvolatile polarization hold great promise for next-generation electronics and photovoltaics. Here, we report reconfigurable band alignment in van der Waals heterostructures based on CuInP2S6 (CIPS) combined with hexagonal boron nitride (h-BN) and graphene (GR), arising from coupled ionic displacement and ferroelectric polarization. Driven by the Cu+ ion-related energy landscape, the ferroelectric polarization order acts as a "pump" that modulates interfacial charge transfer, band alignment configurations, and carrier transport barriers in ferroionic heterostructures. In the h-BN/CIPS stack, polarization switching converts the band alignment from type-H to type-II and reduces the switching barrier to ∼230 meV across the insulating interface. In contrast, in the GR/CIPS heterostructure, it transforms an n-type Schottky barrier into a quasi-Ohmic contact while preserving bistable polarization behavior up to 370 K and producing an asymmetric switching potential with a barrier height of ∼260 meV. These findings highlight the distinct modulation of electronic structure and transport characteristics under different contact environments for ferroionic heterostructures.
