Room temperature ferroelectricity in monolayer graphene sandwiched between hexagonal boron nitride

• Published in: Nature communications Vol. 16; no. 1; pp. 1189 - 8
• Main Authors: Lin, Fanrong, Xuan, Xiaoyu, Cao, Zhonghan, Zhang, Zhuhua, Liu, Ying, Xue, Minmin, Hang, Yang, Liu, Xin, Zhao, Yizhou, Gao, Libo, Guo, Wanlin, Liu, Yanpeng
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 30.01.2025; Nature Publishing Group; Nature Portfolio
• Subjects: 639/766/119/996; 639/925/918/1052; Bilayers; Boron; Boron nitride; Capacitance; Electric polarization; Ferroelectric materials; Ferroelectricity; Ferroelectrics; Graphene; Heterostructures; Humanities and Social Sciences; Interlayers; Memory devices; Monolayers; multidisciplinary; Multilayers; Polarization; Robustness; Room temperature; Science; Science (multidisciplinary); Sliding
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-025-56065-9

The ferroelectricity in stacked van der Waals multilayers through interlayer sliding holds great promise for ultrathin high-density memory devices, yet mostly subject to weak polarization and cryogenic operating condition. Here, we demonstrate robust room-temperature ferroelectricity in monolayer graphene sandwiched between hexagonal boron nitride layers with a rhombohedral-like stacking ( i.e ., ABC-like stacking). The system exhibits an unconventional negative capacitance and record high electric polarization of 1.76 μC/cm 2 among reported sliding ferroelectrics to date. The ferroelectricity also exists in similarly sandwiched bilayer and trilayer graphene, yet the polarization is slightly decreased with odd-even parity. Ab initio calculations suggest that the ferroelectricity is associated with a unique switchable co-sliding motion between graphene and adjacent boron nitride layer, in contrast to existing conventional vdW sliding ferroelectrics. As such, the ferroelectricity can sustain up to 325 K and remains intact after 50000 switching cycles in ~300000 s duration at 300 K. These results open a new opportunity to develop ultrathin memory devices based on rhombohedral-like heterostructures. Here, the authors report that a single-layer graphene sandwiched between hexagonal boron nitride layers in oblique-stacking order exhibits robust ferroelectricity persisting up to room temperature and ultrastability for long-term operations.