EAGER: Experimental studies of electrical double-layer capacitance of graphene using van der Waals heterostructures

非技术：基于石墨烯的电化学器件在传感和储能应用方面表现出了良好的前景。基于石墨烯的电化学晶体管也被证明可以记录大脑中的电信号。对这一系列设备感兴趣的一个主要原因是它们易于制造和操作简单。使用电化学设备的新应用需要将这些设备密集地集成到大规模功能系统中。然而，这仍然是一项艰巨的挑战。在减小器件尺寸时，很难保持高性能和低变化性。纳米制造的进步使电化学设备小型化成为可能，但要完全理解控制其运行的潜在物理原理，仍需做大量工作。这一知识对于实现电化学装置的系统缩小是必不可少的。该项目将通过研究强关联量子系统中的电容来朝着这一目标取得重要进展。技术：单位面积的双电层电容是工程微型电化学设备性能的关键指标。利用石墨烯电子能带结构研究单位面积电容是研究石墨烯双电层电容的一个重要新方向。在这一新的研究方向的启发下，本研究为微型化石墨烯电化学器件的双电层电容的精确工程探索了新的范式。这种模式包括增强石墨烯中的电子和电解液中的离子之间的相关性。这项研究的研究方法是跨学科的，因为它将使用量子物理中先进的范德瓦尔斯石墨烯异质结构来探索电化学中的一个长期问题。具体地说，范德华石墨烯异质结构将被用作测试器件结构，在构建异质结构的过程中，石墨烯上的电势分布将被调节。为了研究石墨烯中的电势分布对双电层电容的影响，将通过电容-电压和伏安测量对器件进行电学表征。拟议的研究项目可能会使石墨烯中的电容能够以纳米级的精度进行精确的工程设计，同时揭示出一条超越目前限制的提高其可实现值的途径。该项目还将培训重要科学领域的学生，并为他们提供设备物理、纳米制造和分析方法方面的专业知识。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。

Nontechnical:Electrochemical devices based on graphene have shown promise for sensing and energy storage applications. Graphene-based electrochemical transistors have also been demonstrated to record electrical signals in the brain. A major reason for interest in this family of devices is their ease of fabrication and simple operation. New applications using electrochemical devices require dense integration of these devices into large-scale functional systems. This has, however, remained a difficult challenge. It is difficult to maintain high performance and low variability when reducing device dimensions. Advances in nanofabrication make it possible to miniaturize electrochemical devices, but much work still needs to be done to fully understand the underlying physics that governs their operation. This knowledge is essential to enable systematic downscaling of the electrochemical devices. This project will make important progress towards that goal by studying capacitance in a strongly correlated quantum system.Technical:Electrical double-layer capacitance per unit area is a key metric for engineering the performance of miniaturized electrochemical devices. An important new research direction for studying the electrical double-layer capacitance of graphene is to investigate the capacitance per unit area with the aid of graphene electronic band structure. Inspired by this new research direction, the proposed research explores a new paradigm for precise engineering of the electrical double-layer capacitance of miniaturized graphene electrochemical devices. This paradigm involves enhancing the correlation between electrons in graphene and ions in the electrolyte. The research approach in this study is interdisciplinary in that it will use advanced van der Waals graphene heterostructures from quantum physics to explore a longstanding question in electrochemistry. Specifically, van der Waals graphene heterostructures will be used as the test device structure, where the potential profile across graphene will be tuned during the construction of the heterostructure. To study the effect of the potential profile in graphene on the electrical double-layer capacitance, the devices will be electrically characterized using capacitance-voltage and voltammetry measurements. The proposed research project may enable accurate engineering of the capacitance in graphene with nanoscale precision, while revealing a pathway for increasing its achievable value beyond the current limits. This project will also trai of students in important scientific areas and provide them with expertise in device physics, nanofabrication, and analysis methods.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.