Transforming Noble Metal Nanostructure Synthesis Using Unconventional Synthetic Levers

非技术摘要：支撑电子工业的是一门以晶片为基础的加工科学，它能够形成不同材料的复杂图案，这些材料具有明确的属性和界面，共同执行有用的功能。最大的挑战之一是建立相应的加工科学，将这些基于晶片的技术与来自金属纳米颗粒的非凡的光学、电子和化学特性相结合。然而，由于无法在有组织的图案中定义复杂的金属纳米结构，在这些图案中，相邻结构之间以及与底层晶片材料的相互作用是可能的，这阻碍了器件原型的制作。正在进行的项目旨在通过重新定义定义基于晶片的金属纳米结构所需的方法、仪器和加工科学来克服这一障碍，并在这样做的过程中提供传统方法无法获得的能力。研究活动正在与本科教育相结合，本科教育包括监督工程学院学生的研究实习，以促进实验室仪器的进步。外展活动的重点是让妇女进入工程专业。技术摘要：正在进行的研究旨在了解当人们熟知的种子介导的贵金属纳米结构生长模式受到四个非传统合成杠杆影响时所产生的化学变化，当种子固定在刚性晶体衬底上时，这些杠杆变得容易接触到。它建立在一种能够通过三步合成方案实现复杂贵金属纳米结构的周期性阵列的合成策略上，该合成方案使用(I)光刻定义的荫罩在特定位置制造纳米结构前驱体，(Ii)定向组装将其转化为单晶模板，以及(Iii)基于溶液的化学进一步将其转化为复杂的纳米结构。在这一战略的范围内，存在着将一组新的合成杠杆纳入纳米结构合成的机会，这些合成杠杆从根本上改变了现有的增长模式。该项目正在推进四种这样的合成杠杆的使用和理解：(I)反应物流过固定衬底，(Ii)合成活性衬底材料，(Iii)衬底外延，以及(Iv)光刻施加的生长障碍。研究生正在接受纳米结构合成和表征、光刻技术以及纳米结构表面制备方面的培训。因此，这项工作有助于更宏伟的愿景，即将纳米材料的非凡物理化学性质与基于晶片的材料、加工技术和电子设备相结合。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Non-Technical Abstract:Underpinning the electronics industry is a wafer-based processing science that is able to form intricate patterns of dissimilar materials with well-defined properties and interfaces that collectively perform a useful function. One of the biggest challenges is the establishment of a corresponding processing science that integrates these wafer-based technologies with the extraordinary optical, electronic, and chemical properties derived from metallic nanoparticles. Device prototyping has, however, been stifled by an inability to define complex metal nanostructures in organized patterns where interactions are possible between adjacent structures and with the underlying wafer material. The project being carried out aims to overcome this impediment by redefining the methodologies, instrumentation, and processing science needed to define wafer-based metal nanostructures, and in doing so, provide the capabilities inaccessible through conventional methods. The research activities are being integrated with undergraduate education that involves the supervision of research internships geared toward the advancement of laboratory instrumentation by students from the College of Engineering. Outreach activities place emphasis on the matriculation of women into the engineering profession.Technical Abstract:The research being carried out aims to provide an understanding of the altered chemistry that arises when well-understood seed-mediated noble metal nanostructure growth modes are subjected to four unconventional synthetic levers that become accessible when seeds are immobilized on a rigid crystalline substrate. It is founded on a synthetic strategy that is able to realize periodic arrays of complex noble metal nanostructures through a three stage synthetic scheme that uses (i) a lithography-defined shadow mask to fabricate nanostructured precursors at site-specific locations, (ii) directed assembly to transform them into single crystal templates, and (iii) solution-based chemistry to further transform them into complex nanostructures. Within the scope of this strategy lies the opportunity to incorporate a new set of synthetic levers into nanostructure synthesis that fundamentally alter well-established growth modes. The project is advancing the use and understanding of four such synthetic levers: (i) a flow of reactants past an anchored substrate, (ii) synthetically-active substrate materials, (iii) substrate-imposed epitaxy, and (iv) lithographically-imposed barriers to growth. Graduate students are being trained in nanostructure synthesis and characterization, lithographic techniques, and the preparation nanostructured surfaces. This work is, hence, contributing to the grander vision that sees the extraordinary physicochemical properties of nanomaterials united with the wafer-based materials, processing techniques, and electronic devices.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.