Balgley Jesse, Butler Jackson, Biswas Sananda, Ge Zhehao, Lagasse Samuel, Taniguchi Takashi, Watanabe Kenji, Cothrine Matthew, Mandrus David G, Velasco Jairo, Valentí Roser, Henriksen Erik A
Department of Physics, Washington University in St. Louis, 1 Brookings Drive, St. Louis, Missouri 63130, United States.
Institut für Theoretische Physik, Goethe-Universität Frankfurt, 60438 Frankfurt am Main, Germany.
Nano Lett. 2022 May 25;22(10):4124-4130. doi: 10.1021/acs.nanolett.2c00785. Epub 2022 May 9.
We demonstrate ultrasharp (≲10 nm) lateral p-n junctions in graphene using electronic transport, scanning tunneling microscopy, and first-principles calculations. The p-n junction lies at the boundary between differentially doped regions of a graphene sheet, where one side is intrinsic and the other is charge-doped by proximity to a flake of α-RuCl across a thin insulating barrier. We extract the p-n junction contribution to the device resistance to place bounds on the junction width. We achieve an ultrasharp junction when the boundary between the intrinsic and doped regions is defined by a cleaved crystalline edge of α-RuCl located 2 nm from the graphene. Scanning tunneling spectroscopy in heterostructures of graphene, hexagonal boron nitride, and α-RuCl shows potential variations on a sub 10 nm length scale. First-principles calculations reveal that the charge-doping of graphene decays sharply over just nanometers from the edge of the α-RuCl flake.
我们利用电子输运、扫描隧道显微镜和第一性原理计算，在石墨烯中展示了超尖锐（≲10纳米）的横向p-n结。p-n结位于石墨烯片层不同掺杂区域的边界处，其中一侧为本征态，另一侧通过跨越薄绝缘势垒靠近α-RuCl薄片进行电荷掺杂。我们提取了p-n结对器件电阻的贡献，以确定结宽度的范围。当本征区和掺杂区之间的边界由距离石墨烯2纳米的α-RuCl解理晶体边缘定义时，我们实现了超尖锐结。石墨烯、六方氮化硼和α-RuCl异质结构中的扫描隧道光谱显示，在亚10纳米长度尺度上存在电位变化。第一性原理计算表明，石墨烯的电荷掺杂在距α-RuCl薄片边缘仅几纳米的范围内急剧衰减。
