纳米材料

正大面积单晶石墨烯薄膜快速制备技术取得突破据报道,近期,北京市科技计划课题"大面积单晶石墨烯薄膜快速制备技术研究"验收通过专家组验收。石墨烯材料性质优异,可用于构筑高性能微纳电子器件和柔性透明导电薄膜,同时也能作为优异的支撑、封装和阻隔材料。大面积高质量的石墨烯薄膜是这些高端应用的材料基础。作为制备大面积高质量石墨烯薄膜材料的首选方法,化学气相沉积法制备的石墨烯薄膜存在畴区尺寸小、晶界和缺陷密度高、大     

等离子体增强化学气相沉积可控制备石墨烯研究进展EI北大核心CSCD

石墨烯具有超薄的结构、优异的光学和电学等性能,在晶体管、太阳能电池、超级电容器和传感器等领域具有极大的应用潜能。为更好地发展实际应用,高质量石墨烯的可控制备研究尤为重要。等离子体增强化学气相沉积(PECVD)技术具有低温和原位生长的优势,成为未来石墨烯制备方面较具潜力的发展方向之一。本文综述了PECVD技术制备石墨烯的发展,重点讨论了PECVD过程中等离子体能量、生长温度、生长基底和生长压力对石墨烯形核及生长的作用,概述了PECVD制备石墨烯的形核及聚结机制、刻蚀和边缘生长竞争两种不同机制,并指出PECVD技术制备石墨烯面临的挑战及发展。在未来的研究中,需突破对石墨烯形核及生长的控制,实现低温原位的大尺寸、高质量石墨烯薄膜的可控制备,为PECVD基石墨烯器件在电子等领域的应用奠定基础。     

等离子体增强化学气相沉积可控制备石墨烯研究进展

石墨烯具有超薄的结构、优异的光学和电学等性能,在晶体管、太阳能电池、超级电容器和传感器等领域具有极大的应用潜能。为更好地发展实际应用,高质量石墨烯的可控制备研究尤为重要。等离子体增强化学气相沉积(PECVD)技术具有低温和原位生长的优势,成为未来石墨烯制备方面较具潜力的发展方向之一。本文综述了PECVD技术制备石墨烯的发展,重点讨论了PECVD过程中等离子体能量、生长温度、生长基底和生长压力对石墨烯形核及生长的作用,概述了PECVD制备石墨烯的形核及聚结机制、刻蚀和边缘生长竞争两种不同机制,并指出PECVD技术制备石墨烯面临的挑战及发展。在未来的研究中,需突破对石墨烯形核及生长的控制,实现低温原位的大尺寸、高质量石墨烯薄膜的可控制备,为PECVD基石墨烯器件在电子等领域的应用奠定基础。     

宝安石墨烯薄膜的制备和转移方法专利获批

正中国宝安子公司深圳市贝特瑞纳米科技有限公司申报的"一种石墨烯透明薄膜的制备和转移方法"(专利号:CN201210235069.3)已由国家知识产权局下发专利证书。专利摘要显示,该发明的目的是提供一种石墨烯透明薄膜的制备和转移方法,要解决的技术问题是降低石墨烯透明薄膜     

中国攻克技术难题石墨烯进入“膜时代”

据报道,中航工业北京航空材料研究院（以下简称“航材院”）日前宣布,已突破制备大尺寸、高质量石墨烯薄膜的技术难题,掌握了衬底材料表面晶粒定向受控生长和化学气相沉积（CVD）反应气体分压配比等关键专利技术,在铜箔表面制备出超过12英寸的石墨烯薄膜,更大尺寸的石墨烯薄膜制备技术也已突破,近期将批量生产,使大尺寸、高质量石墨烯薄膜的工程化制备成为现实,标志着石墨烯制备进入了“膜时代”。     

冷壁CVD法制备石墨烯装置的工艺参数在线量值保证系统研究

目前已使用CVD法在Cu箔上制备出了迄今最大面积(约30英寸)的石墨烯,而且较易于转移到各种基体上使用,因此,该方法被广泛用于制备石墨烯晶体管和透明导电薄膜,已逐渐成为制备高质量石墨烯的主要方法。但是,目前冷壁CVD法制备石墨烯存在的关键技术难题是:不同批次制备的石墨烯产品质量差异较大和同批次制备的石墨烯产品均匀性较差。因此,开展石墨烯制备过程中的工艺参数在线准确测量和量值保证方法研究,为解决石墨烯制备的关键技术难题,实现石墨烯从制备走向量产具有非常重要的意义。     

石墨烯薄膜的制备方法及应用研究进展

完美石墨烯由于具有高导电性、高透光性、高柔韧性、高阻隔性、高机械强度、高化学稳定性、超薄等特性,被誉为21世纪最具颠覆性的"新材料之王",引起全球各界的关注,并预期在电子领域、光子领域、能源领域、环保领域、生物医疗健康等领域具有广阔的发展前景。目前,欧洲、美国、日本等众多国家,都把石墨烯列为本世纪最重要的新材料进行研究和开发,并已在新能源、电子等方面取得重要进展和初步应用效果。我国也明确把石墨烯作为国家重要战略材料列入国家"十三五"规划。石墨烯分为石墨烯粉体(还原氧化石墨烯)和石墨烯薄膜两大类。目前研究较多的是石墨烯粉体,且其制备和应用方面都有了系统的研究,并取得了一定成果。对于石墨烯薄膜,研究较多的是其制备技术,虽然对石墨烯薄膜在各个领域的应用均进行了初步研究,验证了它应用于其中的可行性,并预期其在部分应用领域具有显著优势,但多数处于研究初期,还面临众多技术挑战。因为目前制备的石墨烯薄膜性能和理论性能有较大差距,所以需要研究者们一方面改进制备技术,提升石墨烯薄膜性能;另一方面结合石墨烯特性选择拥有显著优势的应用领域进行深入研究,设计能够体现石墨烯薄膜性能优势的产品器件,这样才能真正打开石墨烯薄膜的应用市场。本文首先介绍了化学气相沉积法制备石墨烯薄膜的研究现状及发展趋势。目前,石墨烯薄膜晶畴尺寸多为微米级到毫米级,少数研究机构所制的石墨烯薄膜晶畴可达到厘米级;石墨烯薄膜迁移率一般可达到10 000～30 000 cm~2/(V·s),方阻小于150Ω/,透光率达到97. 7%。石墨烯薄膜发展趋势是开发可控、快速制备大面积、大晶畴、高质量原位沉积石墨烯薄膜的技术和找到可体现石墨烯薄膜优异性能的应用场景。其次在欧盟"石墨烯旗舰计划"科技路线图的框架下,根据石墨烯薄膜的诸多预期特性,结合技术先进性、未来市场规模、可行性、开发周期等方面,选定16项主要应用方向作为重点关注方向,并将其归为七大类应用:透明导电层、分离隔离膜、场效应晶体管(沟道层)、光电探测器(有源区)、导热材料、集流体涂层、催化剂载体。本文重点系统地分析了石墨烯薄膜在上述应用中预期带来的优势、现状和面临的问题,为石墨烯薄膜材料的发展提供研究基础。     

石墨烯的化学气相沉积法制备

化学气相沉积(CVD)法是近年来发展起来的制备石墨烯的新方法,具有产物质量高、生长面积大等优点,逐渐成为制备高质量石墨烯的主要方法.通过简要分析石墨烯的几种主要制备方法(胶带剥离法、化学剥离法、SiC外延生长法和CVD方法)的原理和特点,重点从结构控制、质量提高以及大面积生长等方面评述了CVD法制备石墨烯及其转移技术的研究进展,并展望了未来CVD法制备石墨烯的可能发展方向,如大面积单晶石墨烯、石墨烯带和石墨烯宏观体的制备与无损转移等.     

基于化学气相沉积石墨烯的传感器的研究进展

作为一种二维碳原子层材料,石墨烯(Graphene,G)具有优异且独特的力学、电学、光学和热学等性质,在传感检测等领域具有巨大的发展潜力和广阔的应用前景.基于石墨烯材料的传感器具有灵敏度高、响应快、成本低、稳定性好等优点.化学气相沉积(Chemical vapor deposi-tion,CVD)因其优异的可控性和可扩展性而被认为是制备大面积、高质量石墨烯薄膜的有效方法,而且CVD石墨烯薄膜适用于场效应晶体管的制造工艺,因此被广泛应用于物理、化学和生物等传感领域.本文介绍了近年来CVD石墨烯应用于传感检测领域的研究进展,包括制备技术、转移方法、传感特性以及在物理、化学、生物等传感领域的应用,并简要分析了基于CVD石墨烯的传感器所面临的困难与挑战.     

超临界流体剥离制备石墨烯研究进展EI北大核心CSCD

石墨烯作为一种新型二维碳纳米材料,具有极好的物理性质和极大的应用潜力。如何大规模制备高质量、低成本的石墨烯是石墨烯产业化的关键问题。本文综述了石墨烯的制备方法及其优缺点,详细介绍了超临界流体剥离制备石墨烯的原理、研究现状及表征方法。讨论了超声波和芘基聚合物辅助超临界流体剥离制备石墨烯法的特点。超临界流体剥离制备石墨烯法设备简单、条件易达到、产品质量高,为石墨烯的工业化生产提供了新的思路。     

A novel method for large area graphene transfer on the polymer optical fiber

We develop two simple methods-the dip coat stamping and lift-off methods-to transfer large area, high quality graphene films onto the top and side faces of the polymer optical fiber. The graphene films can be synthesized using chemical vapor deposition method on large Cu foils. After synthesis, the graphene films are characterized by scanning electron microscopy, atomic force microscopy and Raman spectroscopy. The polymer optical fiber probe with the transferred graphene film can be used as a chemical sensor for the detection of various organic aerosols.     

High‐ versus Low‐Quality Graphene: A Mechanistic Investigation of Electrografted Diazonium‐Based Films for Growth of Polymer Brushes

Electrografting using aryldiazonium salts provides a fast and efficient technique to functionalize commercially available 3?5 layered graphene (vapour‐deposited) on nickel. In this study, Raman spectroscopy is used to quantify the grafting efficiency of cyclic voltammetry which is one of the most versatile, yet simple, electrochemical techniques available. To a large extent the number of defects/substituents introduced to the basal plane of high‐quality graphene by this procedure can be controlled through the sweeping conditions employed. After extended electrografting the defect density reaches a saturation level (～10¹³ cm^?2) which is independent of the quality of the graphene expressed through its initial content of defects. However, it is reached within fewer voltammetric cycles for low‐quality graphene. Based on these results it is suggested that the grafting occurs (a) directly at defect sites for, in particular, low‐quality graphene, (b) directly at the basal plane for, in particular, high‐quality graphene, and/or (c) at already grafted molecules to give a mushroom‐like film growth for all films. Moreover, it is shown that a tertiary alkyl bromide can be introduced at a given surface density to serve as radical initiator for surface‐initiated atom transfer radical polymerization (SI‐ATRP). Brushes of poly(methyl methacrylate) are grown from these substrates, and the relationship between polymer thickness and sweeping conditions is studied.     

纳米石墨烯复合材料的制备及应用研究进展

石墨烯作为一种由单原子紧密堆积成的二维蜂窝状晶格结构碳材料,具有许多特殊的物理化学性质,使其在各个领域均表现出良好的应用前景。目前石墨烯及纳米石墨烯复合材料的制备和应用已成为材料界研究的重点和热点。在简要介绍石墨烯的结构和性质的基础上,介绍了石墨烯的4种制备方法——机械剥离法、化学气相沉积法、化学剥离法和化学合成法。总结了纳米石墨烯/聚合物复合材料以及纳米无机/石墨烯复合材料的制备及应用,并重点讨论了纳米石墨烯复合材料在生物医药、电子器件、微波吸收、传感器以及电极材料等方面独特的应用优势,展望了纳米石墨烯复合材料的发展前景及研究方向。     

Graphene synthesis by ion implantation

We demonstrate an ion implantation method for large-scale synthesis of high quality graphene films with controllable thickness. Thermally annealing polycrystalline nickel substrates that have been ion implanted with carbon atoms results in the surface growth of graphene films whose average thickness is controlled by implantation dose. The graphene film quality, as probed with Raman and electrical measurements, is comparable to previously reported synthesis methods. The implantation synthesis method can be generalized to a variety of metallic substrates and growth temperatures, since it does not require a decomposition of chemical precursors or a solvation of carbon into the substrate.     

铜基底化学气相沉积石墨烯的研究现状与展望

采用粉末包埋法在中国低活性铁素体马氏体钢（RAFM）基底上制备了低活性渗铝层,利用扫描电镜（SEM）和能谱分析（EDS）对渗铝层的形貌和成分进行了分析。结果表明：低活性渗铝层表面铝含量（原子分数）约40％,主要由厚度为15-20μm的FeAl、Fe3-Al及α-Fe（Al）相组成,该渗铝层表面易发生烧结。为避免表面烧结...     

Substrate considerations for graphene synthesis on thin copper films

Chemical vapor deposition on copper substrates is a primary technique for synthesis of high quality graphene films over large areas. While well-developed processes are in place for catalytic growth of graphene on bulk copper substrates, chemical vapor deposition of graphene on thin films could provide a means for simplified device processing through the elimination of the layer transfer process. Recently, it was demonstrated that transfer-free growth and processing is possible on SiO(2). However, the Cu/SiO(2)/Si material system must be stable at high temperatures for high quality transfer-free graphene. This study identifies the presence of interdiffusion at the Cu/SiO(2) interface and investigates the influence of metal (Ni, Cr, W) and insulating (Si(3)N(4), Al(2)O(3), HfO(2)) diffusion barrier layers on Cu-SiO(2) interdiffusion, as well as graphene structural quality. Regardless of barrier choice, we find the presence of Cu diffusion into the silicon substrate as well as the presence of Cu-Si-O domains on the surface of the copper film. As a result, we investigate the choice of a sapphire substrate and present evidence that it is a robust substrate for synthesis and processing of high quality, transfer-free graphene.     

Graphene growth at the interface between Ni catalyst layer and SiO2/Si substrate

Graphene was synthesized deliberately at the interface between Ni film and SiO2/Si substrate as well as on top surface of Ni film using chemical vapor deposition (CVD) which is suitable for large-scale and low-cost synthesis of graphene. The carbon atom injected at the top surface of Ni film can penetrate and reach to the Ni/SiO2 interface for the formation of graphene. Once we have the graphene in between Ni film and SiO2/Si substrate, the substrate spontaneously provides insulating SiO2 layer and we may easily get graphene/SiO2/Si structure simply by discarding Ni film. This growth of graphene at the interface can exclude graphene transfer step for electronic application. Raman spectroscopy and optical microscopy show that graphene was successfully synthesized at the back of Ni film and the coverage of graphene varies with temperature and time of synthesis. The coverage of graphene at the interface depends on the amount of carbon atoms diffused into the back of Ni film.     

Centimeter-scale high-resolution metrology of entire CVD-grown graphene sheets

A high-throughput metrology method for measuring the thickness and uniformity of entire large-area chemical vapor deposition-grown graphene sheets on arbitrary substrates is demonstrated. This method utilizes the quenching of fluorescence by graphene via resonant energy transfer to increase the visibility of graphene on a glass substrate. Fluorescence quenching is visualized by spin-coating a solution of polymer mixed with fluorescent dye onto the graphene then viewing the sample under a fluorescence microscope. A large-area fluorescence montage image of the dyed graphene sample is collected and processed to identify the graphene and indicate the graphene layer thickness throughout the entire graphene sample. Using this metrology method, the effect of different transfer techniques on the quality of the graphene sheet is studied. It is shown that small-area characterization is insufficient to truly evaluate the effect of the transfer technique on the graphene sample. The results indicate that introducing a drop of acetone or liquid poly(methyl methacrylate) (PMMA) on top of the transfer PMMA layer before soaking the graphene sample in acetone improves the quality of the graphene dramatically over immediately soaking the graphene in acetone. This work introduces a new method for graphene quantification that can quickly and easily identify graphene layers in a large area on arbitrary substrates. This metrology technique is well suited for many industrial applications due to its repeatability and flexibility.     

石墨烯基复合材料的三维组装与应用研究进展

三维石墨烯结构体不仅继承了二维石墨烯片完美的碳晶体结构,还展现出超低的密度、极高的孔隙率和较大的比表面积等特点,具有导电、导热、吸附等优异性能,是近年来石墨烯功能材料中的一颗新星。目前,石墨烯与聚合物、无机纳米材料组装成三维结构复合材料的研究已经取得了实质性进展,研究者通过丰富的化学和物理路径实现了石墨烯与功能组分的三维有序组装,并赋予该材料奇特的结构特点和性能优势。这些特性使材料在能量储存、环境保护、传感器等研究领域表现出不错的应用前景。根据当前研究热点,综述了石墨烯基复合材料的三维组装与应用的研究进展,包括三维石墨烯/聚合物复合材料与三维石墨烯/无机纳米复合材料两种体系。重点总结了两种体系的三维组装方法,并分析了复合材料中石墨烯与功能组分的结构特点,简要概括了当前三维石墨烯基复合材料在环境保护、超级电容器等不同领域的应用进展,并对三维石墨烯基复合材料的三维结构设计与多样化应用进行了展望。