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Chemical strategies for tuning the properties of transition metal dichalcogenides

Speaker: 
Damien Voiry (Materials Science and Engineering, Rutgers University)
Date: 
Wed, 28/01/2015 - 11:00am to 12:00pm
Location: 
Physics Conference Room (S13-M01-11)
Host: 
Goki Eda
Event Type: 
Seminars

Abstract

Among the family of 2D materials, transition metal dichalcogenides (TMDs) have demonstrated original opto-electronic properties. For example, the band structure of TMDs can be largely tuned by changing the elemental composition, the thickness or the atomic structure. Single layer TMDs exist in 2 crystalline forms depending on the coordination of the metal atoms: either a trigonal prismatic coordination (2H phase: semiconducting) or an octahedral coordination (1T phase: metallic) [1]. In our group we have actively studied the controlled synthesis of the 1T phase using a well-established procedure based on the lithium intercalation of the 2H phase [2]. The metallic 1T phase has been used for improving the electrocatalytic activity [3,4] or reducing the contact resistance of electronic TMD-based devices [5]. In addition we have recently demonstrated that the 1T phase of group 6 TMDs is chemically activated and can be functionalized covalently in order to further modify the nanosheets [6]. In this presentation, I will introduce the results of our investigations on the phase engineering of exfoliated TMDs in order to ellucidate the importance of the structure in low dimension materials.

[1] Chhowalla, M. et al. Nat. Chem. 5, 263–275 (2013).
[2] Eda, G. et al. Nano Lett. 11, 5111–5116 (2011).
[3] Voiry, D. et al. Nat. Mater. 12, 850–855 (2013).
[4] Voiry, D. et al. Nano Lett. 13, 6222–6227 (2013).
[5] Kappera, R. et al. Nat. Mater. 13, 1128–1134 (2014).
[6] Voiry, D. et al. Nat. Chem. 7, 45–49 (2015).

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