RUI: A New Approach for the Synthesis of Heteroatom-Doped Graphene and Lateral Heterojunctions

RUI：一种合成杂原子掺杂石墨烯和横向异质结的新方法

• 批准号: 1809805
• 负责人: Li Gao
• 金额: $ 18.73万
• 依托单位: The University Corporation, Northridge
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-07-01 至 2022-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1809805&HistoricalAwards=false
• 关键词: RUI; New; Approach; Synthesis; Heteroatom

Nontechnical Description: Graphene is the first discovered two-dimensional material with many exotic properties, however, its flexibility and practical applications remain restrained by some of its specific characteristics. Substitutional doping of graphene with heteroatoms (atoms from chemical elements different from the host material atoms) is one of the most fascinating strategies for tuning graphene's properties and hence expanding its applications. This project investigates the synthesis of heteroatom-doped graphene and related lateral junctions using heteroatom-containing source materials, which is a novel synthesis approach and enhances the capabilities for controlling the doping. This research also provides an atomic-scale understanding of the structural and electronic properties, as well as their interrelations. The realization of controlled synthesis of heteroatom-doped graphene and atomic-scale insights into their properties promote the development of graphene-based devices for electronics, energy storage, and catalysis. This project strengthens the materials science research at California State University Northridge, which is a minority serving institution, and provides collaborative research opportunities for graduate and undergraduate students. In addition, K-12 students from local schools receive exposure to cutting-edge research activities and advanced scientific facilities via summer activities.Technical Description: Precisely controlling the doping properties is pivotal toward practical applications of graphene. Doping properties strongly depend on synthesis approaches, heteroatom sources, and synthesis parameters. It is an urgent task to explore new synthesis approaches and new heteroatom sources in order to achieve enhanced control over the doping strategies. In addition, two-dimensional graphene p-n heterojunctions are the key components for graphene-based electronics, which further motivates the development of bottom-up growth approaches for these heterojunctions. The objectives of this research are to develop optimized synthesis strategies for heteroatom-doped graphene and related lateral heterojunctions from heteroatom-containing sole precursors, which is a novel and effective synthesis approach, as well as to gain atomic-scale insights into the correlations between doping alternatives and electronic properties. To accomplish these goals, the main research activities include: (1) optimize the synthesis by employing a series of precursor/metal systems under varied synthesis conditions and identify the dependence of structural and doping properties (concentration, spatial distribution, and configuration) on precursors, substrates, and synthesis parameters; (2) explore electronic properties (band structure, charge carrier density, work function) by combining scanning tunneling microscopy (STM), X-ray photoelectron spectroscopy, Raman spectroscopy, and angle-resolved photoemission spectroscopy measurements; (3) improve the synthesis of graphene lateral p-n heterojunctions using sole precursors, and characterize the atomic structure and band alignments at the interfaces of lateral heterojunctions by using STM measurements.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.

非技术描述：石墨烯是第一个被发现的具有许多奇异性质的二维材料，然而，它的灵活性和实际应用仍然受到其一些特定特性的限制。石墨烯与杂原子(来自不同于主体材料原子的化学元素的原子)的替代掺杂是调整石墨烯性能从而扩大其应用的最吸引人的策略之一。本项目研究了利用含杂原子的源材料合成掺杂石墨烯及其相关的侧结，这是一种新的合成方法，提高了控制掺杂的能力。这项研究还提供了原子尺度的结构和电子性质的理解，以及它们之间的相互关系。杂原子掺杂石墨烯的可控合成的实现和对其性质的原子尺度的深入了解促进了基于石墨烯的电子学、储能和催化器件的发展。该项目加强了加州州立大学北岭分校的材料科学研究，该大学是一所少数族裔服务机构，并为研究生和本科生提供合作研究机会。此外，来自当地学校的K-12学生通过暑期活动接触到尖端研究活动和先进的科学设施。技术描述：精确控制掺杂性质是石墨烯实际应用的关键。掺杂性质与合成方法、杂原子源和合成参数密切相关。为了加强对掺杂策略的控制，探索新的合成方法和新的杂原子源是当务之急。此外，二维石墨烯p-n异质结是基于石墨烯的电子学的关键部件，这进一步推动了这些异质结自下而上生长方法的发展。本研究的目的是从含杂原子的单一前驱体出发，开发一种新的有效的合成方法，优化合成含杂原子的石墨烯及其相关的侧向异质结，并在原子尺度上深入了解掺杂方式与电子性质之间的关系。为了实现这些目标，主要的研究活动包括：(1)在不同的合成条件下通过采用一系列前驱体/金属体系来优化合成，并确定结构和掺杂性质(浓度、空间分布和构型)对前驱体、衬底和合成参数的依赖关系；(2)结合扫描隧道显微镜(STM)、X射线光电子能谱、拉曼光谱和角度分辨光电子能谱测量来探索电子性质(能带结构、载流子密度、功函数)；(3)使用单一前驱体改进石墨烯横向p-n异质结的合成，并通过STM测量表征横向异质结界面的原子结构和能带排列。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。

项目成果

Atomic-scale identification of nitrogen dopants in graphene on Ir(111) and Ru(0001)

• DOI: 10.1088/1361-648x/ace229
• 发表时间: 2023-06
• 期刊: Journal of Physics: Condensed Matter
• 作者: Huan Yang;Ivan Abilio;Juan Bernal Romero;C. Rodriguez;Miguel Escobar Godoy;Mitchell Little;Patrick Mckee;Vanessa Carbajal;Joey Li;Xing Chen;Hong-Jun Gao;Krisztián Palotás;Li Gao

Nitrogen-Doped Graphene on Copper: Edge-Guided Doping Process and Doping-Induced Variation of Local Work Function

• DOI: 10.1021/acs.jpcc.8b11261
• 发表时间: 2019-03
• 期刊: The Journal of Physical Chemistry C
• 作者: J. Neilson;Harutiun Chinkezian;H. Phirke;Alexander Osei-Twumasi;Yanbang Li;Carlos Chichiri;Jongweon Cho;K. Palotás;L. Gan;S. Garrett;K. Lau;Li Gao