【6th.Jul.】Bottom-Up Synthesis and Characterizations of Graphene Nanoribbons with Controlled Structures and Properties
日期：2016-07-06
阅读：585
TOPIC：Bottom-Up Synthesis and Characterizations of Graphene Nanoribbons with Controlled Structures and Properties
SPEAKER：Dr. Akimitsu Narita, Max Planck Institute for Polymer Research
TIME：July 6 (Wednesday)PM14:00
LOCATION：Room 410, Chemistry Building B (化学B楼410会议室)
INVITER： Prof. Xinliang Feng (冯新亮 教授)，A. Prof. Dongqing Wu (吴东清 副教授)
Abstract:
In contrast to the zero-bandgap graphene, laterally confined graphene nanoribbons (GNRs) possess open bandgaps, which render them highly interesting for the nanoelectronic and optoelectronic applications. Theoretical and experimental studies have revealed that the properties of the GNRs are defined by their structures, in particular the width and the edge configuration. The precise control of the GNR structures is thus essential to reproducibly obtain desired optical and electronic properties. Nevertheless, the required precision cannot be achieved by the predominant “top-down” fabrication methods, such as lithographic “cutting” of graphene sheets and “unzipping” of carbon nanotubes. In this talk, I will present our “bottom-up” approach for the synthesis of structurally defined GNRs,1,2 which can be performed “in solution” by the conventional synthetic chemistry3–5 as well as “on surface” using the modern techniques in physics.6 GNRs could be characterized by various spectroscopic methods, such as IR, Raman, solid-state NMR, and UV-vis absorption spectroscopy, and scanning probe microscopy. Moreover, modulation of the bandgap has been achieved by changing the GNR structure,1 e.g., lateral extension of the GNR to the width of ~2 nm lowered optical bandgap down to ~1.2 eV.4 The GNRs can be longer than 600 nm and liquid-phase processable with the peripheral alkyl chains,3 which enabled fabrication of transistor devices with GNR films as well as on isolated GNR strands.7 Such narrow GNRs with strong absorption in the visible to near-infrared region further displayed interesting photophysical properties such as exciton-exciton annihilation and stimulated emission,8 marking their potential for applications in optoelectronic and photonic devices.
References
1. A. Narita, X.-Y. Wang, X. Feng, K. Müllen, Chem. Soc. Rev. 2015, 44, 6616-6643.
2. A. Narita, X. Feng, K. Müllen, Chem. Rec. 2015, 15, 295.
3. A. Narita, X. Feng, Y. Hernandez, S. A. Jensen et al., Nature Chem. 2014, 6, 126.
4. A. Narita, I. A. Verzhbitskiy, W. Frederickx, K. S. Mali et al., ACS Nano 2014, 8, 11622.
5. M. G. Schwab, A. Narita, Y. Hernandez et al., J. Am. Chem. Soc. 2012, 134, 18169.
6. J. Cai, P. Ruffieux, R. Jaafar, M. Bieri et al., Nature 2010, 466, 470.
7. A. N. Abbas, G. Liu, A. Narita, M. Orosco et al., J. Am. Chem. Soc. 2014, 136, 7555.
8. G. Soavi, S. Dal Conte, C. Manzoni, D. Viola et al., Nat. Commun. 2016, 7, 11010.
