Lou Shuo, Lyu Bosai, Chen Jiajun, Zhou Xianliang, Jiang Wenwu, Qiu Lu, Shen Peiyue, Ma Saiqun, Zhang Zhichun, Xie Yufeng, Wu Zhenghan, Chen Yi, Xu Kunqi, Liang Qi, Watanabe Kenji, Taniguchi Takashi, Xian Lede, Zhang Guangyu, Ouyang Wengen, Ding Feng, 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 Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China.
Nano Lett. 2024 Jan 10;24(1):156-164. doi: 10.1021/acs.nanolett.3c03534. Epub 2023 Dec 26.
Graphene nanoribbons (GNRs), quasi one-dimensional (1D) narrow strips of graphene, have shown promise for high-performance nanoelectronics due to their exceptionally high carrier mobility and structurally tunable bandgaps. However, producing chirality-uniform GNRs on insulating substrates remains a big challenge. Here, we report the successful growth of bilayer GNRs with predominantly armchair chirality and ultranarrow widths (<5 nm) on insulating hexagonal boron nitride (h-BN) substrates using chemical vapor deposition (CVD). The growth of GNRs is catalyzed by transition metal nanoparticles, including Fe, Co, and Ni, through a unique tip-growth mechanism. Notably, GNRs catalyzed by Ni exhibit a high purity (97.3%) of armchair chirality. Electron transport measurements indicate that the ultrathin bilayer armchair GNRs exhibit quasi-metallic behavior. This quasi-metallicity is further supported by density functional theory (DFT) calculations, which reveal a significantly reduced bandgap in bilayer armchair GNRs. The chirality-specific GNRs reported here offer promising advancements for the application of graphene in nanoelectronics.
石墨烯纳米带（GNRs）是石墨烯的准一维（1D）窄带，由于其极高的载流子迁移率和结构可调的带隙，在高性能纳米电子学方面展现出了潜力。然而，在绝缘衬底上制备手性均匀的GNRs仍然是一个巨大的挑战。在此，我们报道了使用化学气相沉积（CVD）在绝缘的六方氮化硼（h-BN）衬底上成功生长出主要为扶手椅型手性且宽度超窄（<5 nm）的双层GNRs。GNRs的生长由包括Fe、Co和Ni在内的过渡金属纳米颗粒通过独特的尖端生长机制催化。值得注意的是，由Ni催化的GNRs表现出高达97.3%的扶手椅型手性纯度。电子输运测量表明，超薄双层扶手椅型GNRs表现出准金属行为。密度泛函理论（DFT）计算进一步支持了这种准金属性，该计算揭示了双层扶手椅型GNRs中的带隙显著减小。本文报道的手性特异性GNRs为石墨烯在纳米电子学中的应用提供了有前景的进展。
