Details
| Original language | English |
|---|---|
| Pages (from-to) | 958-967 |
| Number of pages | 10 |
| Journal | Journal of Physical Chemistry C |
| Volume | 124 |
| Issue number | 1 |
| Early online date | 9 Dec 2019 |
| Publication status | Published - 9 Jan 2020 |
Abstract
The strong sensitivity of plasmonic excitations on nanostructures to their environment is studied, going to the ultimate limit of single atomic chains. As a first step, we investigated how metallicity in self-assembled arrays of Au chains on Si(557) is modified by the simplest possible adsorbate, namely, atomic hydrogen. Both experimental studies and ab initio simulations were carried out combining plasmon spectroscopy with atomistic first-principles density functional calculations (DFT). While metallicity, in general, is only distorted by H-induced disorder, we also observed band gap opening in the measured plasmon dispersion at large momenta, k∥, that limits the plasmonic excitation to an energy of 0.43 eV in the presence of H. In the long-wavelength limit, disorder leads to plasmonic standing wave formation on short sections of wires and finite excitation energies for k∥ → 0. DFT shows that Si surface bands strongly hybridize with those of Au so that H adsorption on the energetically most favorable sites at the Si step edge and the restatom chain not only causes a significant shift of bands but also strongly changes the character of hybridization. Together with H-induced changes in band order, this causes band gap opening and reduced overlap of wave functions. These mechanisms were identified as the main reasons for plasmon localization. Interestingly, although the whole electronic system is modified by H adsorption, there is no direct interaction between H and the Au chains.
ASJC Scopus subject areas
- Materials Science(all)
- Electronic, Optical and Magnetic Materials
- Energy(all)
- General Energy
- Chemistry(all)
- Physical and Theoretical Chemistry
- Materials Science(all)
- Surfaces, Coatings and Films
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In: Journal of Physical Chemistry C, Vol. 124, No. 1, 09.01.2020, p. 958-967.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Plasmon Localization by H-Induced Band Switching
AU - Mamiyev, Z.
AU - Sanna, S.
AU - Ziese, F.
AU - Dues, C.
AU - Tegenkamp, Christoph
AU - Pfnür, Herbert
N1 - Funding Information: The authors gratefully acknowledge financial support from the Deutsche Forschungsgemeinschaft in the research unit FOR 1700 (projects SA 1948/1-2 and TE 386/10-2) and Niedersächsisches Ministerium für Wissenschaft und Kultur through the graduate school “Contacts in Nanosystems”. The Höchstleistungrechenzentrum Stuttgart (HLRS) is gratefully acknowledged for grants of high-performance computer time. The authors acknowledge the computational resources provided by the HPC Core Facility and the HRZ of the Justus-Liebig-Universität Gießen.
PY - 2020/1/9
Y1 - 2020/1/9
N2 - The strong sensitivity of plasmonic excitations on nanostructures to their environment is studied, going to the ultimate limit of single atomic chains. As a first step, we investigated how metallicity in self-assembled arrays of Au chains on Si(557) is modified by the simplest possible adsorbate, namely, atomic hydrogen. Both experimental studies and ab initio simulations were carried out combining plasmon spectroscopy with atomistic first-principles density functional calculations (DFT). While metallicity, in general, is only distorted by H-induced disorder, we also observed band gap opening in the measured plasmon dispersion at large momenta, k∥, that limits the plasmonic excitation to an energy of 0.43 eV in the presence of H. In the long-wavelength limit, disorder leads to plasmonic standing wave formation on short sections of wires and finite excitation energies for k∥ → 0. DFT shows that Si surface bands strongly hybridize with those of Au so that H adsorption on the energetically most favorable sites at the Si step edge and the restatom chain not only causes a significant shift of bands but also strongly changes the character of hybridization. Together with H-induced changes in band order, this causes band gap opening and reduced overlap of wave functions. These mechanisms were identified as the main reasons for plasmon localization. Interestingly, although the whole electronic system is modified by H adsorption, there is no direct interaction between H and the Au chains.
AB - The strong sensitivity of plasmonic excitations on nanostructures to their environment is studied, going to the ultimate limit of single atomic chains. As a first step, we investigated how metallicity in self-assembled arrays of Au chains on Si(557) is modified by the simplest possible adsorbate, namely, atomic hydrogen. Both experimental studies and ab initio simulations were carried out combining plasmon spectroscopy with atomistic first-principles density functional calculations (DFT). While metallicity, in general, is only distorted by H-induced disorder, we also observed band gap opening in the measured plasmon dispersion at large momenta, k∥, that limits the plasmonic excitation to an energy of 0.43 eV in the presence of H. In the long-wavelength limit, disorder leads to plasmonic standing wave formation on short sections of wires and finite excitation energies for k∥ → 0. DFT shows that Si surface bands strongly hybridize with those of Au so that H adsorption on the energetically most favorable sites at the Si step edge and the restatom chain not only causes a significant shift of bands but also strongly changes the character of hybridization. Together with H-induced changes in band order, this causes band gap opening and reduced overlap of wave functions. These mechanisms were identified as the main reasons for plasmon localization. Interestingly, although the whole electronic system is modified by H adsorption, there is no direct interaction between H and the Au chains.
UR - http://www.scopus.com/inward/record.url?scp=85077449418&partnerID=8YFLogxK
U2 - 10.1021/acs.jpcc.9b10688
DO - 10.1021/acs.jpcc.9b10688
M3 - Article
AN - SCOPUS:85077449418
VL - 124
SP - 958
EP - 967
JO - Journal of Physical Chemistry C
JF - Journal of Physical Chemistry C
SN - 1932-7447
IS - 1
ER -