Pinhole evolution of few-layer graphene during electron tunneling and electron transport
Pinhole evolution of few-layer graphene during electron tunneling and electron transport
复制标题
电子隧道和电子传输过程中少层石墨烯的针孔演化
DOI：
10.1016/j.carbon.2018.06.069
复制
发表时间：
2018-11-01
期刊：
影响因子：
10.9
通讯作者：
Deng, Shaozhi
中科院分区：
文献类型：
--
作者：
Tang, Shuai;Zhang, Yu;Deng, Shaozhi
以石墨烯为代表的二维原子晶体是单层或少层的晶体材料。研究二维原子晶体在电子运动过程中的结构演化具有重要意义，因为它关系到材料性质的稳定性和器件应用的可行性。在此，使用原位透射电子显微镜（TEM）观察了电子隧穿和电子传输期间少层石墨烯的针孔演化。对于具有缺陷的少层石墨烯，针孔分别随着电子隧穿电流和时间的增加而扩大。然而，在电子传输过程中，随着电流和时间的增加，石墨烯纳米片中分布的针孔之间可以观察到膨胀和收缩行为。这些行为是升华和自我修复竞争的结果。这两种类型的针孔演化的目的是形成具有较低表面自由能的光滑表面。升华和自修复的临界边界条件由温度、石墨烯针孔结构和活性石墨烯碎片决定。这些发现为石墨烯结构的稳定性和石墨烯基电子器件的可靠性提供了重要的参考。(C)2018爱思唯尔有限公司版权所有。
With graphene as a well-known representative, two-dimensional (2D) atomic crystals are single-layer or few-layer crystalline materials. It is significant to investigate the structure evolution of the 2D atomic crystals in electronic movement process, because it relates to the stability of material properties and the feasibility of the device application. Here, the pinhole evolution of few-layer graphene during electron tunneling and electron transport was observed using in situ transmission electron microscopy (TEM). For few-layer graphene with defects, pinholes expanded with an increase on the electron tunneling current and time, respectively. However, during electron transport processes, with increasing current and time, both, expansion and shrinkage behaviors could be observed among the pinholes distributed within the graphene nanosheet. These behaviors are the result of competition between sublimation and self-repair. Both types of pinhole evolution aim to form a smooth surface with lower surface free energy. The critical boundary conditions for the sublimation and self-repair are determined by the temperature, graphene pinhole structure and active graphene fragment. These findings provide significant reference for the stability of graphene structure and the reliability of graphene based electronic device. (C) 2018 Elsevier Ltd. All rights reserved.