Exploiting nanogap electrodes to probe single nanoparticles, fashion interference-based magnetoresistive materials and develop an electronic surface-dielectric spectroscopy

这项研究将在三个相互关联的前沿推进纳米电子学。由于纳米结构如此之小，探究它们的电学性质是一项挑战。一种常见的方法是在纳米大小的缝隙中加入纳米结构，形成薄（颗粒）薄膜。Dhirani小组观察到，这些广泛使用的设备表现出两个奇怪的现象：它们产生的纳米结构的能级值异常，即使没有纳米结构，它们也倾向于在低电压下表现出“额外”的电流阻力。解决这些问题可以提高对这些纳米探针和纳米结构中电荷流动的理解。后者影响了前沿电子学的许多领域，从分子电子学的研究到纳米结构太阳能电池效率的提高。2)电子干扰：材料科学中出现了一种新兴的想法，即纳米结构可以作为“人造原子”来制造具有“设计”性能的新型“人造材料”。申请人作了生动的示范。十年前，粒状材料被预测具有随电压和磁场振荡的电阻，这一预测首次被申请人的团队证实——多亏了他们使用的“人工材料”。在一系列新的实验中，申请人的团队将通过使用纳米壳作为材料构建块来控制并利用这种效应，从而使这种效应更加明显。这样的演示将代表纳米和材料科学的一次政变，因为它演示了自下而上设计制造一种具有性能的新材料。3)介电感应：利用上述纳米粒子薄膜基础研究的经验教训，申请人小组制造了一种新型的基于电子的化学探测器。这项提议的目标之一是更好地理解这些探测器的工作原理。纳米科学确实可以成为令人兴奋的新纳米技术的沃土：化学探测器在化学工业、制药公司、生物医学实验室、环境实验室、用于医学诊断、药物评估等的生物传感器中无处不在。

This research will advance nanoscale electronics on three interrelated fronts. 1) Since nanostructures are so small, interrogating their electrical properties is challenging. One common way to do this is by incorporating nanostructures in nanometer-sized gaps fashioned in thin (granular) films. The Dhirani group has observed that these widely used devices exhibit two curious phenomena: they yield anomalous values of energy levels of nanostructures and, even without nanostructures incorporated, they tend to exhibit an "extra" resistance to current flow at low voltages. Resolving these issues can lead to an improved understanding of charge flow in these nanoprobes and in nanostructures generally. The latter impacts many areas of interest in cutting edge electronics, ranging from studies of molecular electronics to improved efficiencies for nanostructured solar cells. 2) Electron Interference: There is an emerging idea in materials science that nanostructures may be used as "artificial atoms" to make new types of "artificial materials" with "designer" properties. The applicant has provided a vivid demonstration. A decade ago, granular materials were predicted to possess resistance that oscillated with voltage and magnetic field, a prediction that was confirmed for the first time by the applicant's group - thanks to their use of "artificial materials". In a new series of experiments, the applicant's group will control and, indeed, harness this effect by using nanoshells as material building blocks in order to make the effect even more pronounced. Such a demonstration would represent a coup for nano- and material sciences as it demonstrates fabricating a new material with properties engineered from the bottom-up. 3) Dielectric Sensing: Using lessons learned from the above-mentioned fundamental studies of nanoparticle films, the applicant's group has fabricated a new type of electronics-based chemical detector. One of the goals of this proposal is to better understand the workings of these detectors. Nano-science can indeed be fertile ground for exciting new nanotechnology: chemical detectors are ubiquitous in chemical industries, pharmaceutical companies, biomedical labs, environmental labs, in biosensors for medical diagnostics, drug evaluation, etc.