• 文献标题:   Controlled Quantum Dot Formation in Atomically Engineered Graphene Nanoribbon Field-Effect Transistors
  • 文献类型:   Article
  • 作  者:   EL ABBASSI M, PERRIN ML, BARIN GB, SANGTARASH S, OVERBECK J, BRAUN O, LAMBERT CJ, SUN Q, PRECHTL T, NARITA A, MULLEN K, RUFFIEUX P, SADEGHI H, FASEL R, CALAME M
  • 作者关键词:   graphene nanoribbon, device integration, molecular spectroscopy, coulomb blockade, raman spectroscopy
  • 出版物名称:   ACS NANO
  • ISSN:   1936-0851 EI 1936-086X
  • 通讯作者地址:   Empa
  • 被引频次:   3
  • DOI:   10.1021/acsnano.0c00604
  • 出版年:   2020

▎ 摘  要

Graphene nanoribbons (GNRs) have attracted strong interest from researchers worldwide, as they constitute an emerging class of quantum-designed materials. The major challenges toward their exploitation in electronic applications include reliable contacting, complicated by their small size (<50 nm), and the preservation of their physical properties upon device integration. In this combined experimental and theoretical study, we report on the quantum dot behavior of atomically precise GNRs integrated in a device geometry. The devices consist of a film of aligned five-atom-wide GNRs (5-AGNRs) transferred onto graphene electrodes with a sub 5 nm nanogap. We demonstrate that these narrow-bandgap 5-AGNRs exhibit metal-like behavior at room temperature and single-electron transistor behavior for temperatures below 150 K. By performing spectroscopy of the molecular levels at 13 K, we obtain addition energies in the range of 200-300 meV. DFT calculations predict comparable addition energies and reveal the presence of two electronic states within the bandgap of infinite ribbons when the finite length of the 5-AGNR is accounted for. By demonstrating the preservation of the 5-AGNRs' molecular levels upon device integration, as demonstrated by transport spectroscopy, our study provides a critical step forward in the realization of more exotic GNR-based nanoelectronic devices.