Senkovskiy Boris V, Nenashev Alexey V, Alavi Seyed K, Falke Yannic, Hell Martin, Bampoulis Pantelis, Rybkovskiy Dmitry V, Usachov Dmitry Yu, Fedorov Alexander V, Chernov Alexander I, Gebhard Florian, Meerholz Klaus, Hertel Dirk, Arita Masashi, Okuda Taichi, Miyamoto Koji, Shimada Kenya, Fischer Felix R, Michely Thomas, Baranovskii Sergei D, Lindfors Klas, Szkopek Thomas, Grüneis Alexander
II. Physikalisches Institut, Universität zu Köln, Köln, Germany.
Rzhanov Institute of Semiconductor Physics, Novosibirsk, Russia.
Nat Commun. 2021 May 5;12(1):2542. doi: 10.1038/s41467-021-22774-0.
Lateral heterojunctions of atomically precise graphene nanoribbons (GNRs) hold promise for applications in nanotechnology, yet their charge transport and most of the spectroscopic properties have not been investigated. Here, we synthesize a monolayer of multiple aligned heterojunctions consisting of quasi-metallic and wide-bandgap GNRs, and report characterization by scanning tunneling microscopy, angle-resolved photoemission, Raman spectroscopy, and charge transport. Comprehensive transport measurements as a function of bias and gate voltages, channel length, and temperature reveal that charge transport is dictated by tunneling through the potential barriers formed by wide-bandgap GNR segments. The current-voltage characteristics are in agreement with calculations of tunneling conductance through asymmetric barriers. We fabricate a GNR heterojunctions based sensor and demonstrate greatly improved sensitivity to adsorbates compared to graphene based sensors. This is achieved via modulation of the GNR heterojunction tunneling barriers by adsorbates.
原子精确的石墨烯纳米带（GNR）的横向异质结在纳米技术应用方面颇具前景，但其电荷传输和大多数光谱特性尚未得到研究。在此，我们合成了由准金属和宽带隙GNR组成的多个对齐异质结的单层，并通过扫描隧道显微镜、角分辨光电子能谱、拉曼光谱和电荷传输进行了表征。作为偏置电压、栅极电压、沟道长度和温度函数的综合传输测量表明，电荷传输由隧穿宽带隙GNR段形成的势垒决定。电流-电压特性与通过不对称势垒的隧穿电导计算结果一致。我们制造了一种基于GNR异质结的传感器，并证明与基于石墨烯的传感器相比，其对吸附物的灵敏度有了极大提高。这是通过吸附物对GNR异质结隧穿势垒的调制实现的。
