Electronic band gaps of confined linear carbon chains ranging from polyyne to carbyne
- Author(s)
- Lei Shi, Philip Rohringer, Marius Wanko, Angel Rubio, Sören Waßerroth, Stephanie Reich, Sofie Cambré, Wim Wenseleers, Paola Ayala, Thomas Pichler
- Abstract
Ultralong linear carbon chains of more than 6000 carbon atoms have recently been synthesized within double-walled carbon nanotubes (DWCNTs), and they show a promising route to one-atom-wide semiconductors with a direct band gap. Theoretical studies predicted that this band gap can be tuned by the length of the chains, the end groups, and their interactions with the environment. However, different density functionals lead to very different values of the band gap of infinitely long carbyne. In this work, we applied resonant Raman excitation spectroscopy with more than 50 laser wavelengths to determine the band gap of long carbon chains encapsulated inside DWCNTs. The experimentally determined band gaps ranging from 2.253 to 1.848 eV follow a linear relation with Raman frequency. This lower bound is the smallest band gap of linear carbon chains observed so far. The comparison with experimental data obtained for short chains in gas phase or in solution demonstrates the effect of the DWCNT encapsulation, leading to an essential downshift of the band gap. This is explained by the interaction between the carbon chain and the host tube, which greatly modifies the chain's bond-length alternation.
- Organisation(s)
- Electronic Properties of Materials
- External organisation(s)
- University of the Basque Country, Freie Universität Berlin (FU), University of Antwerp
- Journal
- Physical Review Materials
- Volume
- 1
- No. of pages
- 7
- ISSN
- 2475-9953
- DOI
- https://doi.org/10.1103/PhysRevMaterials.1.075601
- Publication date
- 12-2017
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 103020 Surface physics, 103018 Materials physics, 103009 Solid state physics
- Keywords
- ASJC Scopus subject areas
- Materials Science(all), Physics and Astronomy (miscellaneous)
- Portal url
- https://ucris.univie.ac.at/portal/en/publications/electronic-band-gaps-of-confined-linear-carbon-chains-ranging-from-polyyne-to-carbyne(a960c7e6-f86d-401c-8040-7dcf1585b4a7).html