化学气相传输法控制合成二维 1T-TiSe2 及其电荷密度波转变。
Controlled Synthesis of Two-Dimensional 1T-TiSe with Charge Density Wave Transition by Chemical Vapor Transport.
机构信息
Key Laboratory of Organic Optoelectronics and Molecular Engineering of the Ministry of Education, Department of Chemistry, Tsinghua University , Beijing 100084, China.
Department of Physics, Center for Soft Matter and Biological Physics, Virginia Polytechnic Institute and State University , Blacksburg, Virginia 24061, United States.
出版信息
J Am Chem Soc. 2016 Dec 21;138(50):16216-16219. doi: 10.1021/jacs.6b10414. Epub 2016 Dec 8.
Two-dimensional (2D) metallic transition metal dichalcogenides (TMDCs), such as 1T-TiSe, are ideal systems for exploring the fundamentals in condensed matter physics. However, controlled synthesis of these ultrathin materials has not been achieved. Here, we explored the synthesis of charge density wave (CDW)-bearing 2D TiSe with chemical vapor transport (CVT) by extending this bulk crystal growth approach to the surface growth of TiSe by introducing suitable growth substrates and dramatically slowing down the growth rate. Sub-10 nm TiSe flakes were successfully obtained, showing comparable quality to the mechanically exfoliated thin flakes. A CDW state with 2 × 2 superstructure was clearly observed on these ultrathin flakes by scanning tunneling microscopy (STM), and the phase transition temperature of these flakes was investigated by transport measurements, confirming the existence of CDW states. Our work opens up a new approach to synthesizing 2D CDW and superconductive TMDCs for exploring new fundamentals and applications in novel electronics.
二维（2D）金属过渡金属二卤化物（TMDCs），如 1T-TiSe，是探索凝聚态物理基本原理的理想体系。然而，这些超薄材料的可控合成尚未实现。在这里，我们通过引入合适的生长衬底和显著降低生长速率，将这种块状晶体生长方法扩展到 TiSe 的表面生长，从而探索了具有电荷密度波（CDW）的 2D TiSe 的化学气相传输（CVT）合成。成功获得了亚 10nm 的 TiSe 薄片，其质量可与机械剥离的薄片相媲美。通过扫描隧道显微镜（STM）清楚地观察到这些超薄薄片上存在具有 2×2 超结构的 CDW 态，并且通过输运测量研究了这些薄片的相变温度，证实了 CDW 态的存在。我们的工作为合成 2D CDW 和超导 TMDCs 开辟了一条新途径，以探索新型电子学中的新基础和应用。
Zotero 插件