Li Xufan, Li Baichang, Lei Jincheng, Bets Ksenia V, Sang Xiahan, Okogbue Emmanuel, Liu Yang, Unocic Raymond R, Yakobson Boris I, Hone James, Harutyunyan Avetik R
Honda Research Institute USA Inc., San Jose, CA 95134, USA.
Mechanical Engineering Department, Columbia University, New York, NY 10025, USA.
Sci Adv. 2021 Dec 10;7(50):eabk1892. doi: 10.1126/sciadv.abk1892.
Transition metal dichalcogenides exhibit a variety of electronic behaviors depending on the number of layers and width. Therefore, developing facile methods for their controllable synthesis is of central importance. We found that nickel nanoparticles promote both heterogeneous nucleation of the first layer of molybdenum disulfide and simultaneously catalyzes homoepitaxial tip growth of a second layer via a vapor-liquid-solid (VLS) mechanism, resulting in bilayer nanoribbons with width controlled by the nanoparticle diameter. Simulations further confirm the VLS growth mechanism toward nanoribbons and its orders of magnitude higher growth speed compared to the conventional noncatalytic growth of flakes. Width-dependent Coulomb blockade oscillation observed in the transfer characteristics of the nanoribbons at temperatures up to 60 K evidences the value of this proposed synthesis strategy for future nanoelectronics.
过渡金属二硫属化物根据层数和宽度展现出多种电子行为。因此，开发简便的可控合成方法至关重要。我们发现镍纳米颗粒既促进了二硫化钼第一层的异质成核，同时又通过气-液-固（VLS）机制催化第二层的同质外延尖端生长，从而得到宽度由纳米颗粒直径控制的双层纳米带。模拟进一步证实了纳米带的VLS生长机制及其与传统非催化片状生长相比高出几个数量级的生长速度。在高达60 K的温度下，纳米带转移特性中观察到的宽度依赖性库仑阻塞振荡证明了这种提出的合成策略对未来纳米电子学的价值。
