Band structure modulation by methoxy-functionalization of graphene nanoribbons

Götz, Alicia; Ruini, Alice; Zheng, Wenhao; Soltani, Paniz; Graf, Robert; Tries, Alexander; Li, Juan; Palma, Carlos Andres; Molinari, Elisa; Wang, Hai; Prezzi, Deborah; Muellen, K.; Narita, Akimitsu

doi:10.1039/d1tc05695f

Cited by 6 publications

(7 citation statements)

References 68 publications

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“…The Raman spectrum obtained on Au is presented in Figure 3c with main peaks at 1587 and 1327 cm −1 , in reasonable agreement with spectra after synthesis. 58 A similar lobed structure can be observed in Figure 3d, where five CGNRs are visible, as identified and confirmed by the excitation and torsional frequency shift images in SI Figure S5. The core of the nanoribbon, thereby, again visible as a lower strip is surrounded by two bright lobes formed by the alkyl chains.…”

Section: Comparison Of Three Types Of Gnrs On Au(111)supporting

confidence: 75%

“…The Raman spectrum obtained on Au is presented in Figure 3 c with main peaks at 1587 and 1327 cm –1 , in reasonable agreement with spectra after synthesis. 58 …”

Section: Resultsmentioning

confidence: 99%

“…FGNRs were synthesized according to the procedure described in ref ( 29 ), OMeCGNR synthesis is described in ref ( 58 ), and CGNRs were prepared according to ref ( 22 ).…”

Section: Methodsmentioning

confidence: 99%

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Solution-Synthesized Extended Graphene Nanoribbons Deposited by High-Vacuum Electrospray Deposition

et al. 2022

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Solution-synthesized graphene nanoribbons (GNRs) facilitate various interesting structures and functionalities, like nonplanarity and thermolabile functional groups, that are not or not easily accessible by on-surface synthesis. Here, we show the successful high-vacuum electrospray deposition (HVESD) of well-elongated solution-synthesized GNRs on surfaces maintained in ultrahigh vacuum. We compare three distinct GNRs, a twisted nonplanar fjord-edged GNR, a methoxy-functionalized “cove”-type (or also called gulf) GNR, and a longer “cove”-type GNR both equipped with alkyl chains on Au(111). Nc-AFM measurements at room temperature with submolecular imaging combined with Raman spectroscopy allow us to characterize individual GNRs and confirm their chemical integrity. The fjord-GNR and methoxy-GNR are additionally deposited on nonmetallic HOPG and SiO2, and fjord-GNR is deposited on a KBr(001) surface, facilitating the study of GNRs on substrates, as of now not accessible by on-surface synthesis.

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Section: Comparison Of Three Types Of Gnrs On Au(111)supporting

confidence: 75%

“…The Raman spectrum obtained on Au is presented in Figure 3 c with main peaks at 1587 and 1327 cm –1 , in reasonable agreement with spectra after synthesis. 58 …”

Section: Resultsmentioning

confidence: 99%

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Solution-Synthesized Extended Graphene Nanoribbons Deposited by High-Vacuum Electrospray Deposition

et al. 2022

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“…GNRs with different shapes and widths can be experimentally synthesized using lithography and bottom-up chemical synthesis using molecular precursors [28][29][30][31][32]. The bandgap engineering and magnetic properties of GNRs have been extensively studied [33][34][35][36][37][38][39][40][41]. Zigzag graphene nanoribbons (ZGNRs) are low-bandgap magnetic semiconductors with antiferromagnetic (AFM) coupling between the opposite edges.…”

Section: Introductionmentioning

confidence: 99%

Broken edge spin symmetry induces a spin-polarized current in graphene nanoribbon

Ali,

Ali

2024

J. Phys. D: Appl. Phys.

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Zig-zag graphene nanoribbons (ZGNRs) are known to possess spin moments at the hydrogen-terminated edge carbon atoms, thus the spin-polarized electron transmission is expected while the current is longitudinally passed through the ZGNRs. However, in pristine ZGNRs, the spin-polarized transmission is not observed due to symmetric anti-parallel distributions of the spin densities between the edges. Here, the hypothesis is, any physical or chemical process that breaks such anti-parallel spin-symmetry can induce spin-polarized transmission in the ZGNRs. In this work, we have established this proof-of-concept by depositing the trimethylenemethane (TMM) radical on 6ZGNRH and investigating the quantum transport properties by employing the density functional theory in conjunction with nonequilibrium Green’s function (DFT-NEGF) method. Although TMM has a high magnetic moment (2 µB ), it does not induce magnetization in 6ZGNRH when TMM is physisorbed. But, during the chemisorption of TMM, it forms the π − π bond with the 6ZGNRH in a particular geometric configuration where the pz orbitals of carbon atoms of TMM have maximum overlap with the pz orbitals of carbon atoms of 6ZGNRH. The chemisorption of TMM transfers the spin moment to 6ZGNRH, which breaks the edge spin-symmetry of pristine 6ZGNRH. The adsorption of TMM radical results in transmission dips in the transmission spectra due to interference between localized states of TMM and 6ZGNRH states. This induces spin-polarized transmission with 60% spin-filtering efficiency (SFE) at zero bias, which can further be enhanced up to 92% by applying the bias voltage of 1.0 V.

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“…Depending on the edge structure these can be divided into metallic zigzag graphene nanoribbons (ZGNRs) and mostly semi-metallic to metallic armchair graphene nanoribbons (AGNRs) [10][11][12]. This produces quasi-1D materials that can produce versatile electronic properties through functionalization [13,14]. Uses can include transport devices, but also biosensing materials [15,16].…”

Section: Introductionmentioning

confidence: 99%

Mechanistic Insights into Electronic Current Flow through Quinone Devices

Conrad,

Alcón,

Tremblay

et al. 2023

Nanomaterials

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Molecular switches based on functionalized graphene nanoribbons (GNRs) are of great interest in the development of nanoelectronics. In experiment, it was found that a significant difference in the conductance of an anthraquinone derivative can be achieved by altering the pH value of the environment. Building on this, in this work we investigate the underlying mechanism behind this effect and propose a general design principle for a pH based GNR-based switch. The electronic structure of the investigated systems is calculated using density functional theory and the transport properties at the quasi-stationary limit are described using nonequilibrium Green’s function and the Landauer formalism. This approach enables the examination of the local and the global transport through the system. The electrons are shown to flow along the edges of the GNRs. The central carbonyl groups allow for tunable transport through control of the oxidation state via the pH environment. Finally, we also test different types of GNRs (zigzag vs. armchair) to determine which platform provides the best transport switchability.

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Band structure modulation by methoxy-functionalization of graphene nanoribbons

Abstract: Graphene nanoribbons (GNRs) are considered as potential candidates for next-generation electronic materials, and chemical functionalization can be an efficient method to modulate their electronic properties. This work presents a solution...

Cited by 6 publications

References 68 publications

Solution-Synthesized Extended Graphene Nanoribbons Deposited by High-Vacuum Electrospray Deposition

Solution-Synthesized Extended Graphene Nanoribbons Deposited by High-Vacuum Electrospray Deposition

Broken edge spin symmetry induces a spin-polarized current in graphene nanoribbon

Mechanistic Insights into Electronic Current Flow through Quinone Devices

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