CAREER: Detailed Characterization of Graphene Quantum Dots of Controlled Size, Shape and Chemistry

学院早期职业发展(Career)补助金提供资金，用于对一种新的纳米切割(纳米级切割)工艺进行详细研究，以生产尺寸(10-100 nm)、形状(正方形、矩形和三角形)和化学(原始和官能化)明确的石墨烯量子点(GQD)，并彻底表征它们的结构、光学和电学性质以及性质-相关性。通过可控地将石墨烯缩小到纳米级的GQD，它的性质可以在广泛的光谱上进行调节，从而大大拓宽了它的应用范围。在本项目中，将利用石墨的纳米切割和随后的剥离来制备大量单分散的、结构和化学可控的GQD。随后将：(A)对纳米切割工艺进行彻底的表征，以确定GQD的尺寸分布、形状一致性、官能化密度、边缘光滑度、缺陷类型和密度、结晶学和纳米切割特性；(B)详细的光学和电学表征(带隙；净载流子迁移率和密度，以及GQD薄膜中的载流子传输机制)；以及(C)建立定义GQD特性的关联和理论模型。相关和模型的结果将被分析，以进一步设计纳米切割过程，以微调GQD的性质。重要纳米材料的生产路线和基本性质相关性的发展使纳米技术发生了革命性的变化。然而，GQD的合成和实验表征一直是一个挑战。如果成功，这项研究的结果将开发一条新的路线来生产定义良好的GQD并揭示它们的基本性质。建立的模型和关联将使直接调整GQD特性和合理设计其在半导体行业的应用成为可能。GQD可能会产生与其他碳纳米材料相同的影响。此外，研究活动将与各种教育努力相结合。纳米加工概念将被纳入堪萨斯州立大学的工程教育，以加强其纳米技术基础；新的纳米加工和纳米技术活动将被添加到大学推广计划中，旨在提高女性/代表性不足的学生对工程学的参与；学生将接触到不同的研究文化，以拓宽他们对科学范围的看法。

This Faculty Early Career Development (CAREER) grant provides funding to conduct a detailed study on a novel nanotomy (nanoscale cutting) process to produce graphene quantum dots (GQDs) of well-defined size (10-100 nm), shape (square, rectangle, and triangle), and chemistry (pristine and functionalized); and to thoroughly characterize their structural, optical and electrical properties and property-correlations. By controllably scaling down graphene into nanosized GQDs, its properties can be tuned over a wide spectrum, thus significantly broadening the scope of its applications. In this project, nanotomy of graphite and its subsequent exfoliation will be employed to produce large-quantities of monodisperse GQDs with controlled structure and chemistry. This will be followed by: (a) thorough characterization of the nanotomy-process to determine the GQD size distribution, shape consistency, functionalization density, edge smoothness, defect types and density, crystallography, and nanotomy characteristics; (b) detailed optical and electrical characterization (band-gap; net carrier mobility and density, and carrier transport mechanism in GQD films); and (c) establishing the correlations and theoretical models defining the GQD properties. The results from the correlations and models will be analyzed to further engineer the nanotomy process to fine-tune GQDs' properties. Development of production-routes and fundamental property-correlations of important nanomaterials have revolutionized nanotechnology. However, synthesis and experimental characterization of GQDs have been a challenge. If successful, the results of this research will develop a novel route to produce well-defined GQDs and uncover their fundamental properties. The models and correlations established will enable direct tuning of GQD properties and rational design of its applications for the semiconductor industry. GQDs could potentially have the same impact that other carbon-nanomaterials have had. Further, the research activities will be integrated with various educational efforts. Nanoprocessing concepts will be incorporated into engineering education at Kansas State University to strengthen its nanotechnology base; new nanoprocessing and nanotechnology activities will be added to university outreach programs designed to improve participation of women/underrepresented students in engineering; and the students will be exposed to diverse research cultures to broaden their perspective on the scope of science.