Department of Applied Physics, Cornell University, Ithaca, NY 14853, USA.
Science. 2012 Jun 1;336(6085):1143-6. doi: 10.1126/science.1218948.
Graphene produced by chemical vapor deposition (CVD) is polycrystalline, and scattering of charge carriers at grain boundaries (GBs) could degrade its performance relative to exfoliated, single-crystal graphene. However, the electrical properties of GBs have so far been addressed indirectly without simultaneous knowledge of their locations and structures. We present electrical measurements on individual GBs in CVD graphene first imaged by transmission electron microscopy. Unexpectedly, the electrical conductance improves by one order of magnitude for GBs with better interdomain connectivity. Our study suggests that polycrystalline graphene with good stitching may allow for uniformly high electrical performance rivaling that of exfoliated samples, which we demonstrate using optimized growth conditions and device geometry.
化学气相沉积（CVD）制备的石墨烯是多晶的，载流子在晶界（GBs）处的散射会降低其性能，使其性能相对于剥离的单晶石墨烯而言有所下降。然而，到目前为止，人们只是间接地研究了晶界的电学性质，而没有同时了解它们的位置和结构。我们首先通过透射电子显微镜对 CVD 石墨烯中的单个晶界进行成像，然后对其进行了电学测量。出乎意料的是，对于具有更好域间连接性的晶界，电导率提高了一个数量级。我们的研究表明，具有良好拼接的多晶石墨烯可能具有均匀的高电性能，可与剥离样品相媲美，我们使用优化的生长条件和器件几何形状证明了这一点。
