EAGER: Strain Engineering the Mechanical Properties of Black Phosphorus

通过这项早期概念探索性研究资助（EAGER），该团队将研究生产磷薄层的可行性，根据测量和理论预测，磷薄层比碳薄层具有更有吸引力的电子特性。由一层或几层原子薄层组成的超薄材料正在研究作为当前硅基微电子学的替代品。磷薄层在变形时的电子特性会发生变化，从而可以通过施加外力进行控制，当放置在柔性材料支架上时，可以提供有趣的设备功能。 该项目将演示宏观和纳米尺度弯曲对磷薄膜电子性能的影响。 能够生产和控制磷的特性将为电子产品带来新的材料和概念。研究原子薄层应变的实验与理论相结合的方法的见解将适用于其他二维材料。 该研究计划与一项外展计划相结合，该计划涉及与西班牙专业工程师协会合作招募学生以及与太阳能汽车项目相关的公共教育。 这项研究的目标是通过将实验实现和表征与计算研究相结合来证明原子薄膜中的应变工程。被称为黑磷的磷同素异形体的二维 (2D) 薄膜将剥离到碳化硅和柔性基板上。 预期黑磷将以取决于磷层的数量和图案尺寸的方式符合碳化硅中的图案。 通过对柔性基板施加力，黑磷将发生应变。 黑磷中引入的应变将通过拉曼光谱和扫描隧道显微镜进行测量。 图案的分层将通过原子力显微镜来测量。 这些实验将通过基于密度泛函的理论进行建模，以获得二维薄膜纳米级机械和电子特性的图像。 对应变的理解和控制将实现一种具有带隙的新型各向异性二维电子材料，并将建立一个强大的平台，用于在石墨烯以外的技术重要的二维薄膜中实现应变工程。

With this EArly-concept Grant for Exploratory Research (EAGER), the team will investigate the feasibility of producing thin layers of phosphorus that, based on measurements and theoretical predictions, have more attractive electronic properties than thin layers of carbon. Ultrathin materials that consist of one or a few atomically-thin layers are being studied as alternatives for current silicon-based microelectronics. The electronic properties of thin layers of phosphorous change when subjected to deformation, enabling control by the application of external forces that would offer interesting device functionality when placed on flexible material supports. This project will demonstrate the effect of macro- and nano-scale bending on the electronic properties of thin phosphorus films. Being able to produce and control the properties of phosphorous would enable new materials and concepts for electronics. Insight from the combined experimental-theoretical approach to investigate strain in atomically thin layers would be applicable to other two-dimensional materials. The research program is integrated with an outreach program involving student recruitment in partnership with the Society of Hispanic Professional Engineers, Inc. and public education in relation to the Solar Vehicle Project. The goal of this research is to demonstrate strain engineering in atomically-thin membranes by combining experimental realization and characterization with computational investigation. Two-dimensional (2D) films of the phosphorus allotrope known as black phosphorus will be exfoliated onto silicon carbide and flexible substrates. It is expected that the black phosphorus will conform to patterns in the silicon carbide in a manner that depends on the number of phosphorus layers and pattern dimensions. The black phosphorus will be strained by application of a force to the flexible substrate. The strain introduced in the black phosphorus will be measured by Raman spectroscopy and scanning tunneling microscopy. The delamination from the patterns will be measured by atomic force microscopy. The experiments will be modeled by density functional-based theory to obtain a picture of the mechanical and electronic properties at the nanoscale in two-dimensional films. The understanding and control of strain will enable a new anisotropic, 2D electronic material that has a bandgap, and will establish a robust platform for achieving strain engineering in technologically important 2D films beyond graphene.