Gan Ziyang, Paradisanos Ioannis, Estrada-Real Ana, Picker Julian, Najafidehaghani Emad, Davies Francis, Neumann Christof, Robert Cedric, Wiecha Peter, Watanabe Kenji, Taniguchi Takashi, Marie Xavier, Biskupek Johannes, Mundszinger Manuel, Leiter Robert, Kaiser Ute, Krasheninnikov Arkady V, Urbaszek Bernhard, George Antony, Turchanin Andrey
Institute of Physical Chemistry, Friedrich Schiller University Jena, 07743, Jena, Germany.
Université de Toulouse, INSA-CNRS-UPS, LPCNO, Toulouse, 31077, France.
Adv Mater. 2022 Sep;34(38):e2205226. doi: 10.1002/adma.202205226. Epub 2022 Aug 21.
One-pot chemical vapor deposition (CVD) growth of large-area Janus SeMoS monolayers is reported, with the asymmetric top (Se) and bottom (S) chalcogen atomic planes with respect to the central transition metal (Mo) atoms. The formation of these 2D semiconductor monolayers takes place upon the thermodynamic-equilibrium-driven exchange of the bottom Se atoms of the initially grown MoSe single crystals on gold foils with S atoms. The growth process is characterized by complementary experimental techniques including Raman and X-ray photoelectron spectroscopy, transmission electron microscopy, and the growth mechanisms are rationalized by first principle calculations. The remarkably high optical quality of the synthesized Janus monolayers is demonstrated by optical and magneto-optical measurements which reveal the strong exciton-phonon coupling and enable an exciton g-factor of -3.3.
报道了大面积Janus硒钼硫化物单层的一锅化学气相沉积（CVD）生长，其顶部（硒）和底部（硫）硫族原子平面相对于中心过渡金属（钼）原子不对称。这些二维半导体单层的形成是通过热力学平衡驱动的，将最初生长在金箔上的钼硒单晶底部的硒原子与硫原子进行交换。生长过程通过包括拉曼光谱和X射线光电子能谱、透射电子显微镜在内的互补实验技术进行表征，并且生长机制通过第一性原理计算得到合理解释。光学和磁光测量证明了合成的Janus单层具有极高的光学质量，这些测量揭示了强激子-声子耦合，并实现了-3.3的激子g因子。
