One-dimensional hybrid nanostructure arrays from pi-conjugated organic small molecules and inorganic semiconductors for use in excitonic devices

这项研究计划的主要主题是有机和无机半导体组成的有组织的“混合”一维(1-D)纳米结构的生长、表征和器件应用。一维半导体结构，如纳米管(NTS)和纳米线(NWS)，表现出独特的纳米尺度现象(通常不会在块体中观察到)，这种现象源于取向各向异性和尺寸限制效应。它们还被证明可以实现块体性能的增强。由于这些特性，它们可以用于设计非常规材料和器件配置，并有望克服光伏和光子学领域的困难障碍。光子学领域中的一个这样的障碍是大多数传统材料中的三阶非线性极化率(CHI3)的小值，这目前阻碍了实时全息和全光开关领域的进展。另一个障碍是在低成本激子太阳能电池领域，激子扩散瓶颈阻碍了实现更高的能量转换效率。杂化有序纳米结构有可能极大地提高激子器件的性能，克服上述障碍。因此，我们建议利用一维杂化纳米结构的独特性质和结构来获得在激子器件中的优异性能。我们方法的一个显著特点是，我们的目标不是创建纳米复合材料，而是定向和排列的一维NT/NW混合阵列。我们还注意到，关于碳纳米管、金纳米线、二氧化钛纳米管、硅纳米线等的报道都有数百篇。相比之下，pi-共轭有机纳米管和纳米棒阵列几乎没有受到关注，构成了研究的前沿领域。我们研究计划的一个关键组成部分是对由小分子PI共轭体系制成的晶体纳米管和纳米棒阵列的全面研究。另一个组成部分是激子技术的进步，这是一种在pi共轭有机半导体和纳米结构无机半导体中操纵静电束缚激发态的科学和技术。

The major themes of this research program are the growth, characterization and device applications of organized 'hybrid' one-dimensional (1-D) nanostructures composed of both organic and inorganic semiconductors. 1-D semiconductor architectures such as nanotubes (NTs) and nanowires (NWs) exhibit unique nanoscale phenomena (not normally observed in the bulk) which originate in orientation anisotropy and size confinement effects. They have also been demonstrated to achieve enhancement of bulk properties. Due to these characteristics, they can be used to design unconventional material and device configurations and hold the promise of overcoming difficult obstacles in the fields of photovoltaics and photonics. One such obstacle in the area of photonics is the small value of the third order non-linear susceptibility (chi3) in most conventional materials, which is currently impeding progress in the areas of real-time holography and all-optical switching. Another obstacle is in the area of low cost excitonic solar cells where achievement of higher energy conversion efficiencies is impeded by the exciton diffusion bottleneck. Hybrid organized nanostructures have the potential to dramatically improve the performance of excitonic devices and overcome the obstacles mentioned above. Therefore, we propose to exploit the unique properties and architecture of 1-D hybrid nanostructures to obtain superior performance in excitonic devices. A distinguishing feature of our approach is that we aim to create not nanocomposites, but oriented and aligned 1-D hybrid NT/NW arrays. We also note that there are hundreds of reports each on carbon nanotubes, gold nanowires, titanium dioxide nanotubes, silicon nanowires, etc. In contrast, pi-conjugated organic nanotube and nanorod arrays have received little attention and constitute a frontier area of research. A key component of our research program is the comprehensive study of crystalline nanotube and nanorod arrays made from small-molecule pi-conjugated systems. Another component is the advancement of excitonics, the science and technology of manipulating electrostatically bound excited states in pi-conjugated organic semiconductors and nanostructured inorganic semiconductors.