Posted October 26, 2016 by Rino Rakhmata Mukti, Dr. rer.nat in Guest Seminar

Molecular Functionalization, Graphene Nanoribbons & 2D Heterointerfaces

Prof. Andrew T.S. Wee, National University of Singapore, 26 October 2016, 14.00-15.00

Molecular Functionalization, Graphene Nanoribbons & 2D Heterointerfaces


Andrew T.S. Wee


Department of Physics, National University of Singapore, Singapore 117542



Keywords: molecular functionalization, graphene, nanoribbons, 2D, heterointerfaces


The self-assembly of molecules on surfaces can serve many purposes, including the fabrication of single molecule switches [1]. In particular, pristine graphene does not have an electronic band gap, but its electronic properties can be engineered by molecular adsorption [2,3], or by forming graphene nanoribbons through molecular self-assembly or top-down fabrication methods [4,5]. Unlike graphene, transition metal dichalcogenides (TMDs) such as MoS2 and WSe2, are semiconductors with tunable direct bandgaps dependent on the number of atomic layers, and have potential electronic and optoelectronic applications. We use high resolution scanning tunneling microscopy/spectroscopy (STM/STS) to study the atomic structure, grain boundaries, and intrinsic electronic properties of MoS2 layers (mono-, bi-, tri-) directly deposited on HOPG substrates by chemical vapour deposition (CVD) [6]. We have similarly investigated the atomic scale electronic properties of CVD-grown WSe2 monolayers as well as their interactions with molecules [7,8]. We show that the study of 2D heterointerfaces reveals novel properties and potential applications.


  • [1] J.L. Zhang, J.Q. Zhong, J.D. Lin, W.P. Hu, K. Wu, G.Q. Xu, A.T.S. Wee, W. Chen, Chemical Society Reviews 44 (2015) 2998.
  • [2] W. Chen, S. Chen, D.C. Qi, X.Y. Gao, A.T.S. Wee, Am. Chem. Soc. 129 (2007) 10418.
  • [3] H.Y. Mao, Y. Hong, Y.H. Lu, J.D. Lin, S. Zhong, A.T.S. Wee, W. Chen, Surf. Sci. 88 (2013) 132.
  • [4] H. Huang, D.C. Wei, J.T. Sun, S.L. Wong, Y.P. Feng, A.H. Castro Neto, A.T.S. Wee, Scientific Reports 2 (2012) 983.
  • [5] D.C. Wei, L.F. Xie, K.K. Lee, Z.B. Hu, S.H. Tan, W. Chen, C.H. Sow, K.Q. Chen, Y.Q. Liu, A.T.S. Wee, Nature Comm. 4 (2013) 1374.
  • [6] Y.L. Huang, Y.F. Chen, W.J. Zhang, S.Y. Quek, C.H. Chen, L.J. Li, W.T. Hsu, W.H. Chang, Y.J. Zheng, W. Chen, A.T.S. Wee, Nature Comm. 6 (2015) 6298.
  • [7] Y.L. Huang, Z. Ding, W. Zhang, Y.H. Chang, Y. Shi, L.J. Li, Z. Song, Y.J. Zheng, D. Chi, S.Y. Quek, A.T.S. Wee, Nano Letters 16 (2016) DOI: 10.1021/acs.nanolett.6b00888.
  • [8] Y.J. Zheng, Y.L. Huang, Y.F. Chen, W.J. Zhao, G. Eda, C.D. Spataru, W.J. Zhang, Y.-H. Chang, L.J. Li, D.Z. Chi, S.Y. Quek, A.T.S. Wee, ACS Nano 10 (2016) 2476.


Prof Wee has h-index of 68 as of April 2017.