Large-area electronics based on two-dimensional atomically thin materials

新颖的前沿技术产品，如纸状显示器，可拉伸传感器皮肤，电子纺织品和机器人传感器需要在非常规形状因素基板上进行高速处理，这些基板可以弯曲，灵活，可拉伸，并且可以采用不同的几何形状。因此，需要具有与基于晶圆的传统电子器件同等性能的场效应晶体管，同时具有柔性，与敏感衬底（塑料/橡胶）兼容。由于fet的性能数据与沟道材料及其界面的最终电子特性有着内在的关系，因此需要能够满足上述所有要求的材料。目前，塑料上的大面积电子产品和不寻常的电子产品使用低性能材料，如有机导体或金属氧化物或新兴的硅类材料形成薄膜，这些材料是通过利用现有工业基础设施的多步骤工艺制造的，成本很高。石墨烯由于其机械、电学、光学、化学等特性，已被确定为适用于各种电子技术的电子材料。虽然石墨烯是作为透明电极的理想材料，但它没有带隙阻碍其作为通道材料的使用。在这里，我建议研究一种新的二维原子薄材料，它具有石墨烯的光学和机械特性，但它们具有半导体带隙（1.1-1.9 eV）。此外，它们的高载流子迁移率使它们有别于石墨烯，成为发展异质电子的通道材料。这些材料实际上很有吸引力，因为它们为制造设备提供了现实的途径，因为它们的二维几何形状便于集成，它们在基面上没有悬垂的键，允许在溶液中作为单个粒子进行操作，它们具有独特的机械特性，具有与形状扭曲和折叠相关的效果。同时，它们呈现出量子和其他尺寸相关的效应，导致了丰富的电子、声子动力学和光学特性，这在零和一维材料中是找不到的，为将其应用扩展到自旋电子学、光伏、催化等领域提供了机会。主要目的是演示在逻辑逆变器中工作的低压n/p型场效应管，这是逻辑电子学的基本单元。为此，他们的目标是开发一种新的液相处理方法，将具有保留原子和电子结构的单层薄片从其3D对应物中分离出来，并创建这些血小板的稳定墨水。然后，这些油墨将被用于建立一套可靠的可扩展的确定性组装技术，将薄片以高度均匀的超薄膜的形式大面积地组装到任何基板上。这些材料将与原子级薄的有机电介质相结合，从而确保低功耗运行。此外，二维膜和有机成分在光学范围内都是透明的，因为它们最终的薄厚度导致了半透明器件。在室温下，基于溶液的加工将确保低成本的制造和与任何塑料/橡胶基材的兼容性，并减少制造过程中使用的能源，解决了全球对节能的需求。与现有的电子材料相比，原材料成本也具有竞争力。总的来说，提出的研究可以带来新的经济效益，扩展当前电子技术的前沿，并在新的量子和其他尺寸现象方面开辟基础科学的新场景。

Novel forefront technological products such as, paper like displays, stretchable sensor skin, electronic textiles, and robotic sensors require high speed processing on unconventional form factor substrates, which can be bendable, flexible, stretchable and that they can assume different geometries. Therefore, field effect transistors with performances on a par with the wafer-based conventional electronics and at the same time flexible, compatible with sensitive substrates (plastic/rubber) are required. As the performance figures of FETs are intrinsically related to the ultimate electronic properties of the channel material and its interfaces, the need is to have materials responsive to all aforementioned demands. At present, large area electronics on plastic and unusual format electronics use low performing materials such as organic conductors or metal oxide or alternatively newly emerging Si-like materials shaped into thin membranes, which are fabricated by multi step process exploiting the existing industry infrastructure with the related high costs. Graphene has been identified as a suitable electronic material for all kind of electronic technologies, owing to its mechanical, electrical, optical, chemical properties. Although graphene is the ideal material as a transparent electrode, it does not have a band gap hindering its use as a channel material. Here I propose studying a new range of 2D atomically thin materials, which share optical and mechanical properties of graphene, but in addition they are semiconducting with a band gap (1.1-1.9 eV). Moreover, their high carrier mobility, uniquely distinguishes them from graphene as channel material for development of heterogeneous electronics. These materials are practically appealing as they offer realistic pathways to manufacture devices due to their 2 dimensional geometry facilitating integration, they do not have dangling bonds on the basal plane, allowing manipulation as individual particles in solution and they have unique mechanical features, with effects related to shape distortions and folding. Simultaneously, they present quantum and other size-dependent effects leading to a wealth of electronic, phonon dynamics and optical properties, not found in zero- and one-dimensional materials, offering opportunities to extend the frontiers of their applications to spintronics, photovoltaic, catalysis etc. The main objective is to demonstrate low-voltage n/p-type FETs operating in logic inverters, which are the elemental units of logic electronics.Toward this end, the aim is to develop novel solution phase processing necessary to isolate monolayer flakes with preserved atomic and electronic structure, from their 3D counterpart and create stable inks of these platelets. These inks will be then exploited to establish a reliable array of scalable deterministic assembly techniques of the flakes onto any substrates in the form of highly uniform ultrathin films over large areas. These materials will be interfaced with the atomically thin organic dielectrics, which secure low-power operation. In addition both, 2D membranes as well as the organic components are transparent in the optical range due to their ultimately thin thickness leading to semitransparent devices. The solution based processing at room temperature will ensure low cost manufacturing and compatibility with any plastic/rubber substrates, and reduction of energy employed for fabrication addressing also worldwide need for energy saving. The raw materials cost is also competitive in comparison with the existing materials for electronics. Overall the proposed research can lead to new economic benefits, extend the frontiers of the present electronic technology, and open new scenarios in fundamental science in respect to new quantum and other size-phenomena.