神奇之光助力神奇材料加工  

Miraculous Light Enabling Processing of Magic Materials

作　　者：钟敏霖[1] 范培迅[1] 

机构地区：[1]清华大学材料学院激光材料加工研究中心,北京100084

出　　处：《中国基础科学》2016年第5期43-51,F0004,共10页China Basic Science

基　　金：973计划(2011CB013005)

摘　　要：石墨烯作为一种独特的由碳原子组成的单原子层二维材料,自2004年首次在实验中被制备以来,受到了广泛的关注和研究。石墨烯独特的电学、热学和光学等特性,使其在微电子、储能、透明导电电极以及复合材料等领域有着广阔的应用前景。石墨烯在许多领域的应用对其电子结构、电导率以及透光率等性能有着严格的要求,而这些性能与石墨烯的层数紧密相关。因此,精确的控制石墨烯的层数成为十分重要的研究内容。虽然现有报道提出了一些得到确定层数石墨烯的方法,快速可控得到精确层数石墨烯仍然是现阶段石墨烯应用的一大瓶颈。同时,制备图案化石墨烯也是石墨烯应用中亟需解决的问题。激光是目前最前沿的材料加工和制造手段之一,在现代制造业中扮演了重要角色,已成为国际先进制造技术研究的焦点之一。激光的高亮度、高方向性、高单色性以及典型多维性特征和极端工艺参数使其在加工处理石墨烯方面具备独特优势。结合以上研究热点,本论文提出了一种通过激光辐照的方式对石墨烯进行精确的层数控制、图案化和性能调控的新方法。采用连续CO2激光在真空环境下对石墨烯进行辐照,可将原始多层的石墨烯均匀减薄至2层。采用皮秒激光在大气环境下对石墨烯进行扫描处理,实现多层石墨烯的精确减薄,单次加工即可得到所需层数(1层,2层,3层等)的石墨烯而无需重复加工,并通过图案化的减薄处理,可使不同空间区域具备不同的石墨烯层数。采用飞秒激光切割单层以及多层石墨烯,可简单快捷精确地制备出各种形状和尺寸的石墨烯电子元器件结构。与现有的石墨烯减薄和图案化方法相比,本论文所用方法具有加工过程简单、非接触式加工、环境友好、加工效率高以及加工过程柔性等优势,在石墨烯光电子功能器件领域有着广阔的应用�Graphene, a one-atom thick layer of graphite with densely packed carbon atoms, has been extensively investigated since its first generation in 2004. Depending on its unique properties, graphene is considered to be the next-generation materials of transistors, transparent conductive electrodes and in other applications. The properties of graphene, such as electronic structure and optical transparency are functions of its number of layers （NOL）. Therefore, it is significantly important to accu- rately control the number of graphene layers. Although many groups have reported the synthesizing of monolayer or bilayer graphene, to control the NOL in graphene synthesis is still challenging. Laser is one of the most advanced materials processing and manufacturing methods at present, which has played an important role in the modern manufacturing industry. It has become one of the international research focuses on the advanced manufacturing technologies. The high brightness, high directivity, high monochromaticity and the typical multi- dimensional characteristics as well as extreme technological parameters of laser render it unique advantages in processing graphene. Depending on the above hotspots in graphene and laser materials processing research, we propose a new method for precise thinning and patterning graphene as well as tuning its properties by laser irradiation. The pristine graphene with 5 layers was thinned to 2 layers by CO2 laser in vacuum by vary the laser power density and irradiation time. The thinning process was also achieved by picosecond laser in atmosphere, with multilayer graphene being precisely thinned to specific layer number （1-layer, 2-layer, 3-layer, etc） via only one-step laser processing. The patterned thinning was achieved by programing the laser scanning path. We demonstrate a picosecond laser thinning removal of graphene. Besides, the femtosecond laser was used in patterned cutting graphene. Both monolayer and multilayer graphene can be efficiently and accurately cut into desired d

关 键 词：激光 石墨烯 减薄 图案化 

分 类 号：TQ127.11[化学工程—无机化工] TN249[电子电信—物理电子学]