Group 14 Nanomaterials and Nanoengineered Hybrids – Design, Synthesis, Properties, and Applications.

半导体纳米颗粒，或量子点(QD)大约在30年前首次被报道。当时，很难预见它们将为一个重要的跨学科研究领域提供基础，该领域已在能源生产和储存、高效电子设备、医疗诊断等领域产生深远影响。到目前为止，研究最广泛的量子点是基于CdSe的；这些材料的尺寸依赖性质在很大程度上被理解。尽管镉的精细可调特性和实际应用带来了明显的社会效益，但镉的细胞毒性不容忽视，各国政府正在采取行动限制其使用。 显然，量子点被证明的效用及其对现代社会许多方面的巨大影响的潜力使它们成为非常有吸引力的材料。在这种背景下，人们正在共同努力，以丰富的材料为基础开发无毒的量子点，并建立对影响其性能的参数的理解。硅(Si)和锗(Ge)是有吸引力的CdSe替代品--两者都是半导体，硅是地壳中第二丰富的元素。然而，它们的反应性、电子结构和光学响应与CdSe有很大的不同。事实上，直到最近才开发出方便的方法来制备硅量子点，而制备定义良好的Ge量子点仍然是难以捉摸的。此外，将这些高表面积材料与其周围环境连接起来是一个重要的悬而未决的挑战--如何最好地定制Si和Ge量子点表面化学仍存在争议。此外，关于表面基团如何以及为什么影响这些体系的性质的重要问题仍然存在。如果这些无毒纳米材料要充分发挥其潜力并使社会受益，就必须解决这些问题。 本研究计划的目标是开发制备和定制硅和锗量子点的表面化学的方法。更重要的是，我们的目标是对影响其材料性能的因素建立牢固的理解，这些因素将导致各种有影响力的实际应用(例如，太阳能电池、充电电池、传感器、热电设备和成像剂)的进步。有了这一新的见解，我们将设计、合成和研究结合量子点和聚合物特性的先进纳米工程杂化材料。

Semiconductor nanoparticles, or quantum dots (QDs) were first reported approximately thirty years ago. At that time it was difficult to foresee that they would provide the basis for what has become an important cross-disciplinary research area with far reaching impact in energy production and storage, efficient electronic devices, medical diagnostics, among others. To date, the most widely studied QDs are based upon CdSe; the size dependent properties of these materials are largely understood. Despite the obvious societal benefits afforded by their exquisitely tuneable properties and practical applications, the cytotoxicity of cadmium cannot be ignored and governments are moving to restrict their use. Clearly, the demonstrated utility of QDs and their potential for dramatically impacting many aspects of modern society make them very attractive materials to pursue. In this context, there is a concerted effort to develop non-toxic QDs based upon abundant materials and establish an understanding of the parameters that impact their properties. Silicon (Si) and germanium (Ge) are attractive CdSe alternatives – both are semiconductors and Si is the second most abundant element in the earth’s crust. However, their reactivity, electronic structure, and optical response differ substantially from that of CdSe. In fact, it is only recently that convenient methods for preparing SiQDs were developed and preparation of well-defined GeQDs remains elusive. In addition, interfacing these high surface area materials with their surroundings is an important outstanding challenge – the jury is still out on how best to tailor Si and Ge QD surface chemistry. Furthermore, important questions remain related to how and why surface groups influence the properties of these systems. These issues must be addressed if these non-toxic nanomaterials are to realize their full potential and society is to benefit. The present research program targets the development of methods for preparing and tailoring the surface chemistry of Si and Ge QDs. More importantly, we aim to establish a firm understanding of the factors that influence their material properties which will lead to advances in a variety of impactful practical applications (e.g., solar cells, rechargeable batteries, sensors, thermoelectric devices, and imaging agents). With this new insight in hand, advanced nanoengineered hybrids that marry the properties of quantum dots and polymers will be designed, synthesized, and investigated.