posted on 2017-06-26, 00:00authored byMin Ju, Xiaoyang Liang, Jinxin Liu, Lu Zhou, Zheng Liu, Rafael G. Mendes, Mark H. Rümmeli, Lei Fu
Monolayer transition
metal dichalcogenides (TMDs) possess great
potential in the electronic and optoelectronic devices on account
of their unique electronic structure as well as outstanding characteristics.
However, presented growth approaches are hardly to avoid multilayers
and the root cause of this thermodynamic growth process lies on the
overflowing transition metal sources. Here, a novel substrate-trapping
strategy (STS) is developed to achieve monolayer TMDs crystals over
the whole substrate surface. A designed substrate with appropriate
reaction activity to fix the extra precursors is the key, for which
the dominance of the dynamics will be established, thus leading to
strict self-limited monolayer growth behavior. The high-quality nature
of the synthesized monolayer MoS2 crystals is also clarified
by transmission electron microscopy characterizations and field-effect
transistors performance. Excellent tolerance to variations in growth
parameters of STS is therefore exhibited and, moreover, it is also
verified in achieving strictly monolayer WS2 crystals,
thus demonstrating the universality of this approach. The facile strategy
opens up a new avenue in growth of monolayer TMDs and may facilitate
their industrial applications.