Title: Engineered Materials Genomes of Artificial 2D Lattices

Speaker: Assoc.Prof. Yi-Hsien Lee, Department of Materials Science and Engineering, National Tsinghua University

Date: 2019-04-19 16:30

Location: Room 202, Lujiaxi Building

Abstract：

Monolayers of van der Waals materials, including Graphene or transition metal dichalcogenides (TMDs), are considered ideal building blocks for constructing diverse artificial 2D lattices and hybrid hetero-systems. Heterostructures of nanomaterials, such as lateral multi-junctions of more than two different 2D monolayers, are intriguing for exploring new physics and materials properties.[1-5] Obtaining in-plane heterojunctions of monolayer TMDs with atomically sharp interfaces is very significant for fundamental research and applications. Here, a multistep chemical vapor deposition (CVD) synthesis of the in-plane multi-junctions of monolayer TMDs is presented. With optimized parameters, atomically sharp interfaces are successfully achieved in the synthesis of in-plane artificial lattices of the WS2/WSe2/MoS2 at reduced growth temperatures. Moreover, performances of the 2D monolayers were artificially engineered by geometrically tuning with 1D nanowires arrays or by physically integrating with optical microcavity.[6-8] Artificially engineering of the 2D materials offers an ideal platform to explore new physics and realize industrial applications for next-generation optoelectronics and photonics.

References

[1] Kuan-Chang Chiu, Adv. Mater. 30, 1704796 (2018)

[2] Xi-Ling et al, Adv. Mater., 28 (12), p.2322 (2016)

[3] Xin-Quan Zhang et al, Nano Lett, 15, p.410 (2015)

[4] Lili Yu et al, Nano Lett, 14, p.3055 (2014)

[5] Yi-Hsien Lee, et al., Nano Lett., 13, 1852 (2013)

[6] Xiaoze Liu et al, Nature Photonics, 9, p.30 (2015)

[7] Sam Yang et al, VLSI 2016

[8] Tung-Han Yang et al, Adv. Func. Mater., 28(7), 1706113 (2018)

Biography:

Dr. Yi-Hsien Lee

Associate Professor

Dept. Materials Science and Engineering (MSE),

National Tsing Hua University (NTHU)

E-mail: yhlee.mse@mx.nthu.edu.tw

Web: www.mse.nthu.edu.tw/~yhlee/