发布时间：2025-10-01

文章标题：Nano Letters: Spontaneous Closing of Torn Bilayer Graphene Edges via a Self- Healing Mechanism

内容：

     https://pubs.acs.org/doi/10.1021/acs.nanolett.5c04158

    The electronic transport properties of nanoscale patterned graphene are significantly influenced by its edge structures. Herein, we report a self-healing phenomenon of freshly torn bilayer graphene edges based on in situ scanning tunneling microscopy observations. The fresh bilayer edges are created in the surface graphene layers by tip-induced field evaporation. Surprisingly, atomic resolution images reveal the spontaneous formation of a half-tubular structure that seamlessly connects the upper and lower layers, identical to the edge of a folded monolayer graphene. It is attributed to a self-healing mechanism of open bilayer edges in aligned zigzag (or armchair) direction, where the transient edge carbon radicals evolve into sp² hybridized C-C bonds between neighboring layers. For armchair edges, the original AB stacking can be locked into the AA stacking due to required sliding of carbon atoms. This finding opens up an atomic precision edge engineering method of patterned graphene for devices.

    我们以STM针尖作为原子级制造的工具，实现了超高真空极低温条件下基于场蒸发效应的石墨烯边界切割，并在新制备的双层的zigzag和armchair边界上发现了出乎意料的自发缝合现象，即上下两层边缘碳自由基自发键合形成完美无悬键的半管状封闭结构。其中armchair边界的自缝和还会因一个键长的滑移形成锁定的AA双层堆垛结构。这些发现为不受边缘态影响的高质量石墨烯纳米器件未来原子级制造提供了一种新机制。

This work was done by Xueyan Li (李雪妍），who is currently a Ph.D candidate.