In Situ-Generated Volatile Precursor for CVD Growth of a Semimetallic 2D Dichalcogenide

• Main Authors: Gao, Zhenfei (Author), Ji, Qingqing (Author), Shen, Pin-Chun (Author), Han, Yimo (Author), Leong, Wei Sun (Author), Mao, Nannan (Author), Zhou, Lin (Author), Su, Cong (Author), Niu, Jin (Author), Ji, Xiang (Author), Goulamaly, Mahomed Mehdi (Author), Muller, David A. (Author), Li, Yongfeng (Author), Kong, Jing (Author)
• Other Authors: Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science (Contributor), Massachusetts Institute of Technology. Research Laboratory of Electronics (Contributor), Massachusetts Institute of Technology. Department of Nuclear Science and Engineering (Contributor)
• Format: Article
• Language: English
• Published: American Chemical Society (ACS), 2019-06-27T14:42:35Z.
• Subjects: Article
• Online Access: Get fulltext

Semimetallic-layered transition-metal dichalcogenides, such as TiS2, can serve as a platform material for exploring novel physics modulated by dimensionality, as well as for developing versatile applications in electronics and thermoelectrics. However, controlled synthesis of ultrathin TiS2 in a dry-chemistry way has yet to be realized because of the high oxophilicity of active Ti precursors. Here, we report the ambient pressure chemical vapor deposition (CVD) method to grow large-size, highly crystalline two-dimensional (2D) TiS2 nanosheets through in situ generating titanium chloride as the gaseous precursor. The addition of NH4Cl promoter can react with Ti powders and switch the solid-phase sulfurization reaction into a CVD process, thus enabling the controllability over the size, shape, and thickness of the TiS2 nanosheets via tuning the synthesis conditions. Interestingly, this semimetallic 2D material exhibits near-infrared surface plasmon resonance absorption and a memristor-like electrical behavior, both holding promise for further application developments. Our method hence opens a new avenue for the CVD growth of 2D metal dichalcogenides directly from metal powders and pave the way for exploring their intriguing properties and applications.
National Science Foundation (U.S.) (Grant DMR-1231319)