†Department of Physics and Materials Research Laboratory, University of Illinois at Urbana-Champaign, 1110 West Green Street, Urbana, Illinois 61801, United States.
‡Department of Mechanical Engineering, University of Maryland, College Park, Maryland 20742, United States.
ACS Nano. 2015 Jun 23;9(6):5799-806. doi: 10.1021/acsnano.5b00335. Epub 2015 May 26.
Strain can tune desirable electronic behavior in graphene, but there has been limited progress in controlling strain in graphene devices. In this paper, we study the mechanical response of graphene on substrates patterned with arrays of mesoscale pyramids. Using atomic force microscopy, we demonstrate that the morphology of graphene can be controlled from conformal to suspended depending on the arrangement of pyramids and the aspect ratio of the array. Nonuniform strains in graphene suspended across pyramids are revealed by Raman spectroscopy and supported by atomistic modeling, which also indicates strong pseudomagnetic fields in the graphene. Our results suggest that incorporating mesoscale pyramids in graphene devices is a viable route to achieving strain-engineering of graphene.
应变可以调整石墨烯中理想的电子行为，但在控制石墨烯器件中的应变方面进展有限。在本文中，我们研究了在具有纳米级金字塔阵列图案的衬底上的石墨烯的力学响应。通过原子力显微镜，我们证明了石墨烯的形态可以从共形到悬浮状态进行控制，这取决于金字塔的排列方式和阵列的纵横比。通过拉曼光谱和原子建模揭示了石墨烯在金字塔上悬空时的非均匀应变，原子建模也表明石墨烯中有很强的赝磁场。我们的结果表明，在石墨烯器件中引入纳米级金字塔是实现石墨烯应变工程的一种可行途径。
