Condensed Matter Seminar, Jan. 8
发布时间: 2020-03-11     文章作者:     访问次数: 107

Time: 10:00 AM, January 8 (Tomorrow)
Place: C101, Jiangwan Physics Building

From Theoretical Understanding on the Growth Mechanisms to the
Synthesis of Wafer-scale Single Crystalline 2D Materials

Prof. Feng Ding Department of Material Science and Engineering, Ulsan
National Institute of Science and Technology, Korea

In comparsion with the 3D materials, graphene and most 2D materials owns
the unique properties of the ultra-high flexibility and weak interaction
with a substrate, which distinguish its growth mechanism from those of
the homoepitaxial growth of 3D crystals and heteroepitaxial growth of
thin films. The weak van der Waals interaction between graphene and a
substrate allows a single crystalline graphene island to across a grain
boundary (GB) of the substrate without changing its single
crystallinity. Based on this theoretical prediction, we propose that
wafer scale graphene single crystal could be synthesized on a
polycrystalline substrate via nucleation suppression. [1] Such a
strategy was realized by the method of feedstock local feeding during
graphene CVD growth. [2] The preferential alignment of nucleated
graphene islands on a transition metal surface allows us to grow single
crystalline graphene on a symmetry matching substrate and, therefore,
wafer scale graphene single crystal growth might be achieved on a large
single crystalline substrate.[1,3,4] Experimentally, large area single
crystalline Cu (111) foils was synthesized for the growth of wafer scale
graphene single crystal.[5,6] Besides the (111) surfaces of fcc
crystals, our theoretical analysis predicts that unidirectional growth
of hexagonal boron nitride or other 2D materials could be realized on a
high-index single crystalline metal foil.[7]


[1] X Zhang, et al, (2012), The Journal of Physical Chemistry Letters 3,
[2] T Wu, et al, (2016), Nature materials 15, 43
[3] J Gao, et al, (2011), Journal of the American Chemical Society 133,
[4] Q Yuan, et al, (2014), The journal of physical chemistry letters, 5,
[5] S Jin, et al ,(2018), Science 362, 1021-1025
[6] X Xu, et al, (2017), Science Bulletin 62, 1074-1080
[7] L Wang, et al, (2019) Nature 570, 91-95