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

新型前沿技术产品，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子基板上进行高速处理，这些基板可以是可弯曲的、柔性的、可拉伸的，并且它们可以呈现不同的几何形状。因此，需要具有与基于晶片的常规电子器件相当的性能并且同时具有柔性、与敏感衬底（塑料/橡胶）兼容的场效应晶体管。由于FET的性能数据与沟道材料及其界面的最终电子特性内在相关，因此需要具有响应于所有上述需求的材料。目前，塑料上的大面积电子器件和不寻常格式的电子器件使用低性能材料，例如有机导体或金属氧化物或可替代地新出现的成形为薄膜的类Si材料，其通过利用现有工业基础设施的多步工艺制造，具有相关的高成本。石墨烯具有良好的机械、电学、光学、化学等性能，被认为是一种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，但它不具有阻碍其用作通道材料的带隙。在这里，我建议研究一系列新的2D原子薄材料，它们具有石墨烯的光学和机械特性，但除此之外，它们是半导体，具有带隙（1.1-1.9 eV）。此外，它们的高载流子迁移率使它们与石墨烯独特地区别开来，作为用于开发异质电子器件的沟道材料。这些材料实际上是有吸引力的，因为它们提供了制造器件的现实途径，这是由于它们的二维几何形状促进了集成，它们在基面上没有悬挂键，允许在溶液中作为单个颗粒进行操作，并且它们具有独特的机械特征，具有与形状变形和折叠相关的效果。同时，它们呈现量子和其他尺寸依赖效应，导致丰富的电子，声子动力学和光学特性，在零维和一维材料中没有发现，提供了将其应用扩展到自旋电子学，光伏，催化等前沿的机会。主要目标是展示在逻辑逆变器中工作的低压n/p型FET，为此，目的是开发将具有保留的原子和电子结构的单层薄片与它们的3D对应物隔离所需的新型溶液相处理，并产生这些薄片的稳定油墨。然后，这些油墨将被利用来建立一个可靠的阵列的可扩展的确定性组装技术的薄片到任何基板上的高度均匀的印刷膜的形式在大面积。这些材料将与原子级薄的有机硅连接，从而确保低功耗操作。此外，2D膜以及有机组分由于其最终薄的厚度而在光学范围内是透明的，从而导致半透明装置。在室温下基于溶液的处理将确保低成本制造和与任何塑料/橡胶基材的兼容性，并且减少用于制造的能量，也解决了全球范围内的节能需求。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，拟议的研究可以带来新的经济效益，扩展目前电子技术的前沿，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.