Ouyang Tianyi, Cha Soonyoung, Sun Yiyang, Taniguchi Takashi, Watanabe Kenji, Gabor Nathaniel M, Lui Chun Hung
Department of Physics and Astronomy, University of California Riverside, Riverside, California 92521, United States.
Research Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan.
Nano Lett. 2025 Jan 29;25(4):1459-1465. doi: 10.1021/acs.nanolett.4c05370. Epub 2025 Jan 14.
Transition metal dichalcogenides (TMDs) with rhombohedral (3R) stacking order are excellent platforms to realize multiferroelectricity. In this work, we demonstrate the electrical switching of ferroelectric orders in bilayer, trilayer, and tetralayer 3R-MoS dual-gate devices by examining their reflection and photoluminescence (PL) responses under sweeping out-of-plane electric fields. We observe sharp shifts in excitonic spectra at different critical fields with pronounced hysteresis. These phenomena are attributed to distinct interlayer polarizations resulting from specific lateral displacements between the layers, with each configuration yielding a unique ferroelectric state. Our findings indicate two, three, and four ferroelectric regimes for bilayer, trilayer, and tetralayer structures, respectively, in agreement with theoretical prediction. Moreover, each polarization state can be stabilized at zero applied electric field. The tunable ferroelectric phases of these multilayers pave the way for innovative applications in non-volatile memory, logic circuits, and optoelectronic devices.
具有菱面体（3R）堆叠顺序的过渡金属二硫属化物（TMDs）是实现多铁性的优秀平台。在这项工作中，我们通过在扫描面外电场下检查双层、三层和四层3R-MoS双栅器件的反射和光致发光（PL）响应，展示了铁电序的电开关特性。我们在不同临界场观察到激子光谱的急剧移动，并伴有明显的滞后现象。这些现象归因于层间特定横向位移导致的不同层间极化，每种结构都产生独特的铁电态。我们的发现分别表明双层、三层和四层结构存在两种、三种和四种铁电状态，这与理论预测一致。此外，每个极化状态在零外加电场下都可以稳定。这些多层材料的可调铁电相为非易失性存储器、逻辑电路和光电器件等创新应用铺平了道路。
