Concentration Dependence of Dopant Electronic Structure in Bottom-up Graphene Nanoribbons

• DOI: 10.1021/acs.nanolett.8b00651
• Publication Date: 2018-05-31T18:02:09Z
• Authors: Zahra Pedramrazi; Chen Chen; Fangzhou Zhao; Ting Cao; Giang D. Nguyen; Arash A. Omrani; Hsin-Zon Tsai; Ryan R. Cloke; Tomas Marangoni; Daniel J. Rizzo; Trinity Joshi; Christopher Bronner; Won-Woo Choi; Felix R. Fischer; Steven G. Louie; Michael F. Crommie
• Keywords: 02 engineering and technology; Condensed Matter Physics; 530; Engineering; Physical Sciences; Nanotechnology; Nanoscience & Nanotechnology; Scanning tunneling microscopy; substrate interaction; 0210 nano-technology; backbone boron doping; density functional theory; graphene nanoribbons

Bottom-up fabrication techniques enable atomically precise integration of dopant atoms into the structure graphene nanoribbons (GNRs). Such dopants exhibit perfect alignment within GNRs and behave differently from bulk semiconductor dopants. The effect concentration on electronic GNRs, however, remains unclear despite its importance in future electronics applications. Here we use scanning tunneling microscopy first-principles calculations to investigate bottom-up synthesized N = 7 armchair featuring varying concentrations boron First-principles freestanding predict that inclusion a GNR backbone should induce two sharp states whose energy splitting varies with concentration. Scanning spectroscopy experiments, reveal broad an greater than expected. This anomalous behavior results unusual hybridization between Au(111) surface, dopant-surface interaction strength dictated by orbital symmetry.