Lyu Bosai, Chen Jiajun, Lou Shuo, Li Can, Qiu Lu, Ouyang Wengen, Xie Jingxu, Mitchell Izaac, Wu Tongyao, Deng Aolin, Hu Cheng, Zhou Xianliang, Shen Peiyue, Ma Saiqun, Wu Zhenghan, Watanabe Kenji, Taniguchi Takashi, Wang Xiaoqun, Liang Qi, Jia Jinfeng, Urbakh Michael, Hod Oded, Ding Feng, Wang Shiyong, Shi Zhiwen
Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Shenyang National Laboratory for Materials Science, School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai, 200240, China.
Collaborative Innovation Centre of Advanced Microstructures, Nanjing University, Nanjing, 210093, China.
Adv Mater. 2022 Jul;34(28):e2200956. doi: 10.1002/adma.202200956. Epub 2022 Jun 7.
Graphene nanoribbons (GNRs) with widths of a few nanometers are promising candidates for future nanoelectronic applications due to their structurally tunable bandgaps, ultrahigh carrier mobilities, and exceptional stability. However, the direct growth of micrometer-long GNRs on insulating substrates, which is essential for the fabrication of nanoelectronic devices, remains an immense challenge. Here, the epitaxial growth of GNRs on an insulating hexagonal boron nitride (h-BN) substrate through nanoparticle-catalyzed chemical vapor deposition is reported. Ultranarrow GNRs with lengths of up to 10 µm are synthesized. Remarkably, the as-grown GNRs are crystallographically aligned with the h-BN substrate, forming 1D moiré superlattices. Scanning tunneling microscopy reveals an average width of 2 nm and a typical bandgap of ≈1 eV for similar GNRs grown on conducting graphite substrates. Fully atomistic computational simulations support the experimental results and reveal a competition between the formation of GNRs and carbon nanotubes during the nucleation stage, and van der Waals sliding of the GNRs on the h-BN substrate throughout the growth stage. This study provides a scalable, single-step method for growing micrometer-long narrow GNRs on insulating substrates, thus opening a route to explore the performance of high-quality GNR devices and the fundamental physics of 1D moiré superlattices.
宽度为几纳米的石墨烯纳米带（GNRs）因其结构可调的带隙、超高的载流子迁移率和出色的稳定性，有望成为未来纳米电子应用的候选材料。然而，在绝缘衬底上直接生长微米长的GNRs（这对纳米电子器件的制造至关重要）仍然是一个巨大的挑战。在此，报道了通过纳米颗粒催化化学气相沉积在绝缘的六方氮化硼（h-BN）衬底上外延生长GNRs。合成了长度达10 µm的超窄GNRs。值得注意的是，生长后的GNRs与h-BN衬底在晶体学上对齐，形成一维莫尔超晶格。扫描隧道显微镜显示，在导电石墨衬底上生长的类似GNRs的平均宽度为2 nm，典型带隙约为1 eV。全原子计算模拟支持了实验结果，并揭示了成核阶段GNRs和碳纳米管形成之间的竞争，以及生长阶段GNRs在h-BN衬底上的范德华滑动。这项研究提供了一种可扩展的单步方法，用于在绝缘衬底上生长微米长的窄GNRs，从而开辟了一条探索高质量GNR器件性能和一维莫尔超晶格基本物理的途径。
