Nature Paper - Nanyang Assistant Professor Liu Zheng
We would like to extend our warmest congratulations to Nanyang Assistant Professor Liu Zheng, Professor Shen Zexiang, Dr Zhou Jiadong and Dr Zeng Qingsheng on the publication of their research paper, entitled “A library of atomically thin metal chalcogenides” in Nature.
Abstract
Investigations of two-dimensional transition-metal chalcogenides (TMCs) have recently revealed interesting physical phenomena, including the quantum spin Hall effect, valley polarization and two-dimensional superconductivity, which suggest potential applications for functional devices. However, of the numerous compounds available, only a handful, such as Mo- and W-based TMCs, have been synthesized, typically via sulfurization, selenization and tellurization of metals and metal compounds. Many TMCs are difficult to produce because of the high melting points of their metal and metal oxide precursors. Molten-salt-assisted methods have been used to produce ceramic powders at relatively low temperature and this approach was recently employed to facilitate the growth of monolayer WS2 and WSe2. Here, we demonstrate that molten-salt-assisted chemical vapour deposition can be broadly applied for the synthesis of a wide variety of two-dimensional (atomically thin) TMCs. We synthesized 47 compounds, including 32 binary compounds (based on the transition metals – Ti, Zr, Hf, V, Nb, Ta, Mo, W, Re, Pt, Pd and Fe), 13 alloys (including 11 ternary, 1 quaternary and 1 quinary), and 2 heterostructured compounds. We elaborate how the salt decreases the melting points of the reactants and facilitates the formation of intermediate products, which increases the overall reaction rate. Most of the synthesized materials in our library are useful, as supported by evidence of superconductivity in our monolayer NbSe2 and MoTe2 samples and of high mobilities in MoS2 and ReS2. Although the quality of some of the materials still requires development, our work opens up opportunities for studying the properties and potential applications of a wide variety of two-dimensional TMCs.
The paper can be found via this link: https://www-nature-com.ezlibproxy1.ntu.edu.sg/articles/s41586-018-0008-3
About the journal
Nature is an international journal publishing the finest peer-reviewed research in all fields of science and technology on the basis of its originality, importance, interdisciplinary interest, timeliness, accessibility, elegance and surprising conclusions. Nature also provides rapid, authoritative, insightful and arresting news and interpretation of topical and coming trends affecting science, scientists and the wider public.
Our heartiest congratulations to the team on their excellent achievement!