Graphene Coated Porous Semiconductor Nanocomposites for High Performance Electronics and Photonics

纳米结构半导体材料已经对我们的日常生活产生了重大影响，它使激光、固态照明、强大而快速的电子设备、光子学和高性能太阳能电池等强大的技术成为可能。最近，通过电化学处理对半导体进行了修饰，使单晶变得多孔化，并赋予其新的性质。多孔硅因其具有可见光发射、高比表面积、降低机械硬度或可通过氧化来调节晶格常数等一系列性质而引起人们的极大兴趣。另一方面，石墨烯是一种材料，其性能可能会在传感、储能、电子和光伏等领域产生极具颠覆性的新技术。近年来，我的团队为合成一种特殊的纳米结构材料奠定了基础：纳米和介孔半导体。它们的纳米级内部结构也可以显示出量子限制效应。拟议的五年研究计划将利用多孔半导体结构来结合石墨烯，并将其内表面积包裹起来，形成一种新型的纳米复合材料，称为石墨烯涂层多孔半导体？纳米复合材料。多孔性半导体的高内表面积将允许大量石墨烯的集成，并具有相应的好处。然而，关于合成过程以及它所产生的材料性能，仍有许多需要了解。 我的计划将围绕两个主流进行。第一流将集中在合成过程和它所产生的纳米复合材料性能上。必须了解和优化掺入过程，以产生尽可能接近原始状态的石墨烯形式，以获得充分的好处。我将探索通过改变底层的多孔基质结构(孔隙率、微晶大小)可以获得的性能范围。将研究其机械、热学和传输特性，以及光折变特性。第二个流将利用这些结果来探索新的纳米复合材料可以被开发的可能应用。这种纳米复合材料将作为过渡层用于在硅片上高质量地外延生长GaN。还将研究石墨烯对纳米复合材料温度稳定性的影响，这是成功的必要条件。

Nanostructured semiconductor materials have had a major effect on our daily lives by enabling powerful technologies like lasers, solid-state lighting, powerful and fast electronics, photonics and high performance solar cells. More recently semiconductors were modified through electrochemical processing to make the monocrystal porous and to give it new properties. Porous silicon has attracted a lot of interest for its range of properties, from visible light emission, high specific surface area, reduced mechanical stiffness, or adjustable lattice constant through oxidation. Graphene on the other hand, is a material with properties that can potentially generate highly disruptive new technologies, in sensing, energy storage, electronics and photovoltaics to name a few. In the recent years, my team has laid the foundation for the synthesis of a specific kind of nanostructured material: nano- and meso-porous semiconductors. Their nanometer-scale internal structures can also display quantum confinement effects. The proposed 5-year research program will use the porous semiconductor structure to incorporate graphene and coat its internal surface area to form a new kind of nano-composite, called « graphene-coated porous semiconductor » nano-composite. The high internal surface area of the porous semiconductor will allow the integration of large quantities of graphene with the corresponding benefits. However, much remains to be understood, on the synthesis process as much as on the material properties that it creates. My program will operate around two main streams. The first stream will focus on the synthesis process and nano composite properties that it produces. The incorporation process must be understood and optimized to generate a form of graphene as close as possible to the « pristine » state to gain full benefits. I will explore the range of properties that can be achieved by varying the underlying porous matrix structure (porosity, crystallite size). Mechanical, thermal and transport properties, along with photo refractive properties will be studied. The second stream will use these results to explore possible applications where the new nano composites can be exploited. The nano composite will be used as interlayers for the high quality epitaxial growth of GaN on silicon wafers. The effect of the graphene on the temperature stability of the nano-composite, a necessary condition for success will also be studied.