Growth, Fabrication, and Characterization of Novel Semiconductor Nanostructures

对半导体材料特性的研究是我们技术文明的基础之一。半导体材料提供了用于实现计算机、无线技术、光纤通信和太阳能发电等的电子设备的支柱。这些设备都是基于对基础材料科学及其创新潜力的详细了解。 纳米线是直径在纳米范围（10- 9 m）的半导体材料的非常细的线，由于其非常小的直径而具有不寻常的性质;例如，由于量子效应，电子的性质和行为在非常细的线中是不同的。纳米线的高表面积-体积比是潜在的优点（例如，对于气体传感器）和缺点（例如，用于发光器件和太阳能电池）。近年来，在形成用于许多应用的纳米线的方法方面取得了显著进展，所述应用包括极高速晶体管、太阳能电池、气体传感器、高效发光体和大表面积纳米材料。 这项研究提案的目的是对半导体纳米结构，特别是纳米线的物理学有一个清晰的了解，目的是在设备中使用这些新的结构。实际的半导体器件依赖于材料缺陷：一方面，必须引入杂质以控制导电;另一方面，某些缺陷，例如材料表面出现的缺陷，可能会产生负面影响。这在纳米线中可能是有问题的，其中电子非常接近表面。 该提案侧重于理解半导体纳米线科学的两个关键挑战。首先，我们建议开发新的和控制的方法，用于形成特定的纳米线结构，可用于原型器件的应用，如太阳能电池和发光二极管。这包括开发在可用于形成器件原型的结构中生长特定材料（GaAs、GaN、InAs、ZnO和相关材料）的方法。 第二，我们将开发新的方法，利用先进的电子显微镜方法和低温光学光谱学的半导体纳米线中的电子和空穴的行为的表面和体缺陷的量化作用。我们的双管齐下的方法将使我们能够开发和测试简单的原型纳米线器件结构，这将成为未来工业应用的基础。 拟议的研究将利用我们的成就和合作，并继续在这一领域设定新的方向。该研究计划将培养未来的领导者，配备在半导体生长和表征，电子显微镜技术，谁将有助于研究和工业应用的专业知识。

Research into the properties of semiconductor materials is one of the foundations of our technological civilization. Semiconductor materials provide the backbone of electronic devices used to enable computers, wireless technologies, fibre optic communications, and solar power generation, among others. These devices have all been based on a detailed understanding of fundamental materials science and its potential for innovation. Nanowires are very thin wires of semiconductor materials with diameters in the nanometer range (10-9m) that have unusual properties by virtue of their very small diameters; for example, the properties and behaviour of electrons are different in very thin wires due to quantum effects. The high surface area-to-volume ratio of nanowires is both a potential advantage (e.g., for gas sensors) and a drawback (e.g., for light emitting devices and solar cells). In recent years, there has been significant progress in methods to form nanowires for use in a number of applications, including extremely high speed transistors, solar cells, gas sensors, high efficiency light emitters, and large surface area nanomaterials. The aim of this research proposal is to gain a clear understanding of the physics of semiconductor nanostructures, particularly nanowires, with the goal to use these novel structures in devices. Practical semiconductor devices rely on materials defects: on one hand, impurities must be introduced in order to control electrical conduction; on the other hand, certain defects, such as those that arise at the surfaces of materials, can have a negative effect. This can be problematic in nanowires, where the electrons are in close proximity to the surface. This proposal focuses on two key challenges in understanding the science of semiconductor nanowires. First, we propose to develop novel and controlled methods for the formation of specific nanowire structures that can be used in prototype device applications, such as solar cells and light emitting diodes. This includes developing methods to grow specific materials (GaAs, GaN, InAs, ZnO, and related materials) in structures that can be used to form device prototypes. Second, we will develop new ways of quantifying the role of surface and bulk defects on the behaviour of electrons and holes in semiconductor nanowires using advanced electron microscopy methods and low temperature optical spectroscopy. Our two-pronged approach will enable us to develop and test simple prototype nanowire device structures that will form the basis of future industrial applications. The proposed research will capitalize on our achievements and collaborations, and continue to set new directions in this field. This research program will train future leaders, equipped with expertise in semiconductor growth and characterization, and electron microscopy techniques, who will contribute to both research and industrial applications.