Growth of environmentally stable transition metal selenide films

When:
13/02/2019 @ 10:30 AM – 11:30 AM Asia/Singapore Timezone
2019-02-13T10:30:00+08:00
2019-02-13T11:30:00+08:00
Where:
Seminar Room 2, MD1-08-03E
Growth of environmentally stable transition metal selenide films @ Seminar Room 2, MD1-08-03E

Speaker: Professor Gao Libo
Affiliation: Nanjing University, China
Host: Asst. Prof. Lu Jiong
Location: Click HERE for directions

Abstract Details: Two-dimensional transition metal selenides possess fascinating physical properties. However, most as-prepared selenides are small in size and environmentally unstable, which greatly hinder their wide applications in high-performance electrical devices. Here we develop a general two-step vapour deposition method and successfully grow different selenide films with controllable thickness, wafer size and high crystalline quality. In stark contrast to the poor stability of most two-dimensional materials, these selenide films show superior environmental stability even after long time exposure or being heated in air, annealed in vacuum or immersed in aqueous solutions. The superconductivity of grown NbSe2 film is comparable with sheets cleavaged from bulks, and can well maintain after a variety of harsh treatments. The unique properties of these selenide films can be ascribed to the absence of oxygen during the whole growth process. Such unprecedented environmental stability could greatly simplify devices assembling procedure, and should be of both fundamental and technological significance in developing TMS-based devices with extraordinary performances.

References
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[2] Li, L. J. et al. Nature 2016, 529, 185-189.
[3] Ge, J.-F. et al. Nat. Mater. 2015, 14, 285-289.
[4] Wang, H. et al. Nat. Commun. 2017, 8, 394.
[5] Lin, H. et al. Nat. Mater. 2019 (accept)

About the Speaker: Prof Libo Gao graduated from Institute of Metal Research, Chinese Academy of Sciences, with PhD degree in 2011. Then, he joined Graphene Research Centre, National University of Singapore during 2011 to 2015. After that, he joined Nanjing University with a full professor from May 2015. He focuses his research area in chemical vapor deposition (CVD) growth of graphene from 2008. His group in Nanjing University now focuses on the CVD growth of special graphene (nanocrystalline, nanoribbons, ultra-flat, etc..) and two dimensional superconductors (NbSe2, Mo2C, FeSe…). He has published 32 papers until now, which were cited by more than 8000 times.