Mukhopadhyay T, Mahata A, Adhikari S, Zaeem M Asle
Department of Engineering Science, University of Oxford, Oxford, UK.
Department of Materials Science and Engineering, Missouri University of Science and Technology, Rolla, USA.
Sci Rep. 2017 Nov 17;7(1):15818. doi: 10.1038/s41598-017-15664-3.
Two-dimensional and quasi-two-dimensional materials are important nanostructures because of their exciting electronic, optical, thermal, chemical and mechanical properties. However, a single-layer nanomaterial may not possess a particular property adequately, or multiple desired properties simultaneously. Recently a new trend has emerged to develop nano-heterostructures by assembling multiple monolayers of different nanostructures to achieve various tunable desired properties simultaneously. For example, transition metal dichalcogenides such as MoS show promising electronic and piezoelectric properties, but their low mechanical strength is a constraint for practical applications. This barrier can be mitigated by considering graphene-MoS heterostructure, as graphene possesses strong mechanical properties. We have developed efficient closed-form expressions for the equivalent elastic properties of such multi-layer hexagonal nano-hetrostructures. Based on these physics-based analytical formulae, mechanical properties are investigated for different heterostructures such as graphene-MoS, graphene-hBN, graphene-stanene and stanene-MoS. The proposed formulae will enable efficient characterization of mechanical properties in developing a wide range of application-specific nano-heterostructures.
二维和准二维材料因其令人兴奋的电子、光学、热学、化学和机械性能而成为重要的纳米结构。然而，单层纳米材料可能无法充分具备某一特定性能，或同时具备多种所需性能。最近出现了一种新趋势，即通过组装不同纳米结构的多个单层来开发纳米异质结构，以同时实现各种可调的所需性能。例如，过渡金属二硫属化物（如MoS）展现出有前景的电子和压电性能，但其低机械强度是实际应用中的一个限制因素。考虑石墨烯-MoS异质结构可以缓解这一障碍，因为石墨烯具有很强的机械性能。我们已经为这种多层六角形纳米异质结构的等效弹性性能开发了高效的闭式表达式。基于这些基于物理的解析公式，研究了不同异质结构（如石墨烯-MoS、石墨烯-hBN、石墨烯-锡烯和锡烯-MoS）的机械性能。所提出的公式将能够在开发各种特定应用的纳米异质结构时有效地表征机械性能。
