Lin Fanrong, Xuan Xiaoyu, Cao Zhonghan, Zhang Zhuhua, Liu Ying, Xue Minmin, Hang Yang, Liu Xin, Zhao Yizhou, Gao Libo, Guo Wanlin, Liu Yanpeng
Key Laboratory for Intelligent Nano Materials and Devices of Ministry of Education, State Key Laboratory of Mechanics and Control of Mechanical Structures, and Institute for Frontier Science, Nanjing University of Aeronautics and Astronautics, Nanjing, China.
Zhangjiang Laboratory, Shanghai, China.
Nat Commun. 2025 Jan 30;16(1):1189. 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 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.
通过层间滑动实现的堆叠范德华多层膜中的铁电性，对于超薄高密度存储器件具有巨大潜力，但大多存在极化较弱和需要低温工作条件的问题。在此，我们展示了在具有类菱面体堆叠（即ABC类堆叠）的六方氮化硼层之间夹有单层石墨烯时，能实现稳健的室温铁电性。该体系展现出非常规的负电容，并且在迄今报道的滑动铁电体中，记录到高达1.76 μC/cm²的高极化强度。铁电性同样存在于类似夹芯结构的双层和三层石墨烯中，不过极化强度会随奇偶性略有降低。从头算计算表明，与现有的传统范德华滑动铁电体不同，该铁电性与石墨烯和相邻氮化硼层之间独特的可切换协同滑动运动相关。因此，这种铁电性在高达325 K的温度下仍能维持，并且在300 K下持续约300000秒的50000次开关循环后仍保持完好。这些结果为基于类菱面体异质结构开发超薄存储器件开辟了新机遇。
