Details

Autor(en) / Beteiligte

• Ma, Chuanxu
• Liang, Liangbo
• Xiao, Zhongcan
• Puretzky, Alexander A
• Hong, Kunlun
• Lu, Wenchang
• Meunier, Vincent
• Bernholc, J
• Li, An-Ping

Titel

Seamless Staircase Electrical Contact to Semiconducting Graphene Nanoribbons

Ist Teil von

• Nano letters, 2017-10, Vol.17 (10), p.6241-6247

Ort / Verlag

United States: American Chemical Society

Erscheinungsjahr

2017

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Electrical contact to low-dimensional (low-D) materials is a key to their electronic applications. Traditional metal contacts to low-D semiconductors typically create gap states that can pin the Fermi level (E F). However, low-D metals possessing a limited density of states at E F can enable gate-tunable work functions and contact barriers. Moreover, a seamless contact with native bonds at the interface, without localized interfacial states, can serve as an optimal electrode. To realize such a seamless contact, one needs to develop atomically precise heterojunctions from the atom up. Here, we demonstrate an all-carbon staircase contact to ultranarrow armchair graphene nanoribbons (aGNRs). The coherent heterostructures of width-variable aGNRs, consisting of 7, 14, 21, and up to 56 carbon atoms across the width, are synthesized by a surface-assisted self-assembly process with a single molecular precursor. The aGNRs exhibit characteristic vibrational modes in Raman spectroscopy. A combined scanning tunneling microscopy and density functional theory study reveals the native covalent-bond nature and quasi-metallic contact characteristics of the interfaces. Our electronic measurements of such seamless GNR staircase constitute a promising first step toward making low resistance contacts.