EAGER: Coupled Opto-Electro-Mechanics in Semiconducting Phosphorene

摘要：虽然黑磷早在1914年就被发现，但对其在少数原子层极限下的半导体性质的认识尚处于起步阶段，实验结果很少。到目前为止，这种原子级薄的纳米材料还没有显著的应用来造福社会。这项研究工作将全面研究机械力通过应变作为自由度的影响，以实验方式探测几种现象，包括其晶体结构的变化，光的吸收和发射，以及从半导体行为到金属行为的转变，所有这些都可以用来实现新型光电器件和芯片。鉴于最近在黑磷晶体生长方面的进展，这项关于机械力对其独特的电学和光学性质的强耦合的研究工作可以在实际规模上实现突破性的器件应用。此外，来自不同背景的研究生和本科生将在纳米材料和电子领域进行前沿研究。技术：由于磷烯具有接近石墨烯的高电荷迁移率，并且其厚度可调的带隙可以与半导体过渡金属二硫族化合物一样大，因此它有望成为最具吸引力的二维材料。从本质上讲，磷烯代表了备受追捧的高迁移率，可调谐的直接带隙原子层状晶体，是纳米电子学，光电子学和柔性电子学的理想选择。此外，独特的褶皱晶格提供了石墨烯中所没有的平面内各向异性，导致机械力与电子、光子和声子的强耦合，从而使先进的应变电子学能够用于高效的纳米级能量转换设备和转换柔性技术。提出的努力将集中在机械力在工程上的强耦合，磷烯独特的电学和光学性质，这可能导致突破性的设备应用。研究工作将包括两种实验方法，研究单轴应变对光电性能的影响，以及研究静水压力在触发结构和电子相变中的作用。

Abstract:Non-TechnicalThough black phosphorus was discovered in 1914, understanding of its semiconducting properties in the limit of a few atomic layers are at a nascent state with very few experimental results. There exists no significant application of this atomically-thin nanomaterial to benefit society to date. This research effort will comprehensively investigate the effect of mechanical forces via strain as degrees of freedom for probing several phenomena experimentally including changes in its crystal structure, absorption and emission of light, and transition from a semiconducting to a metallic behavior, all of which, can be utilized to enable novel optoelectronic devices and chips. In light of the recent progress on growing crystals of black phosphorus, this research effort on the strong coupling of mechanical forces on its unique electrical and optical properties can result in breakthrough device applications at practical scales. In addition, graduate and undergraduate students from diverse backgrounds will be trained in conducting research at the frontier of nanomaterials and electronics.Technical:Phosphorene is poised to be the most attractive two-dimensional material owing to its high charge mobilities approaching that of graphene, and its thickness tunable bandgap that can be as large as that of semiconducting transitional metal di-chalcogenides. In essence, phosphorene represents the much sought after high-mobility, tunable direct bandgap atomically layered crystal that is ideal for nanoelectronics, optoelectronics and flexible electronics. In addition, the unique puckered lattice affords in-plane anisotropy that is absent in graphene, leading to strong coupling of mechanical forces with electrons, photons, and phonons that can enable advanced straintronics for efficient nanoscale energy conversion devices and transformational flexible technology. The proposed effort will focus on the strong coupling of mechanical forces on engineering the unique electrical and optical properties of phosphorene that can result in breakthrough device applications. The research effort will consist of two experimental approaches, investigation of the effects of uniaxial strain on the optoelectronic properties, and studies on hydrostatic pressure in triggering structural and electronic phase transitions.