2N+4-rule and an atlas of bulk optical resonances of zigzag graphene nanoribbons

Payod, Renebeth; Grassano, Davide; Santos, Gil Nonato C.; Levshov, Dmitry; Pulci, Olivia; Saroka, V. A.

doi:10.1038/s41467-019-13728-8

Cited by 16 publications

(8 citation statements)

References 67 publications

(93 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Semiconducting materials like graphene nanoribbons (GNR) are among the prime candidates for nanoelectronics. [6][7][8] These flat aromatic macromolecules arranged as narrow strips of graphene are defined by the number N of dimer-lines across their width. Their properties are determined by their edge structure (armchair or zigzag) and width [9,10] but making GNR with atomically precise characteristics involves significant challenges.…”

Section: Introductionmentioning

confidence: 99%

Unravelling the Complete Raman Response of Graphene Nanoribbons Discerning the Signature of Edge Passivation

et al. 2022

View full text Add to dashboard Cite

Controlling the edge morphology and terminations of graphene nanoribbons (GNR) allows tailoring their electronic properties and boosts their application potential. One way of making such structures is encapsulating them inside single‐walled carbon nanotubes. Despite the versatility of Raman spectroscopy to resolve strong spectral signals of these systems, discerning the response of long nanoribbons from that of any residual precursor remaining outside after synthesis has been so far elusive. Here, the terrylene dye is used as precursor to make long and ultra‐narrow armchair‐edged GNR inside nanotubes. The alignment and characteristic length of terrylene encapsulated parallel to the tube's axis facilitates the ribbon formation via polymerization, with high stability up to 750 °C when the hybrid system is kept in high vacuum. A high temperature annealing is used to remove the terrylene external molecules and a subtraction model based on the determination of a scaling factor related to the G‐band response of the system is developed. This not only represents a critical step forward toward the analysis of the nanoribbon‐nanotube system, but it is a study that enables unraveling the Raman signatures of the individual CH‐modes (the signature of edge passivation) for GNR for the first time with unprecedented detail.

show abstract

Section: Introductionmentioning

confidence: 99%

Unravelling the Complete Raman Response of Graphene Nanoribbons Discerning the Signature of Edge Passivation

et al. 2022

View full text Add to dashboard Cite

show abstract

“…These new peaks render TBGQDs for applications on photovoltaic devices and photodetectors. The mapped atlas and constructed selection rule database of optical spectrum present a comprehensive structure/symmetryfunction interrelation and allows an excellent geometrical control of optical properties for TBGQDs as a building block in on-chip carbon optoelectronics [56,57]. The process involves two steps to generate TBGQDs.…”

Section: Discussionmentioning

confidence: 99%

Polarization-dependent selection rules and optical spectrum atlas of twisted bilayer graphene quantum dots

Wang¹,

Yu²,

Rösner³

et al. 2021

Preprint

View full text Add to dashboard Cite

Finding out how symmetry encodes optical polarization information into the selection rule in molecules and materials is important for their optoelectronic applications including spectroscopic analysis, display technology and quantum computation. Here, we extend the polarization-dependent selection rules from atoms to solid systems with point group descriptions via rotational operator for circular polarization and 2-fold rotational operator (or reflection operator) for linear polarization. As a variant of graphene quantum dot (GQD), twisted bilayer graphene quantum dot (TBGQD) certainly inherits GQD's advantages including ultrathin thickness, excellent biocompatibility and shape-and size-tunable optical absorption/emission. We then naturally ask how the electronic structures and optical properties of TBGQDs rely on size, shape, twist angle and correlation effects. We build plentiful types of TBGQDs with 10 point groups and obtain the optical selection rule database for all types, where the current operator matrix elements identify the generalized polarization-dependent selection rules. Our results show that both of the electronic and optical band gaps follow power-law scalings and the twist angle has the dominant role in modifying the size scaling. We map an atlas of optical conductivity spectra for both size and twist angle in TBGQDs. As a result of quantum confinement effect of finite size, in the atlas a new type of optical conductivity peaks absent in twisted bilayer graphene bulk is predicted theoretically with multiple discrete absorption frequencies from infrared to ultraviolet light, enabling applications on photovoltaic devices and photodetectors. The atlas and size scaling provide a full structure/symmetry-function interrelation and hence offers an excellent geometrical manipulation of optical properties of TBGQD as a building block in integrated carbon optoelectronics.

show abstract

“…(1) a pair of carbyne N = 7 and cyclo [18]carbon, and (2) carbyne N = 8 and cyclo [18]carbon pair. Here, we test by the TD-DFT method whether the 2N + 2 rule stated above or the 2N + 4 43 rule applies to the alignment of absorption spectra in a carbyne-cyclo[n]carbon pair. The eigenenergies of molecular orbitals (MO) for each representative carbon allotropes are compared in Fig.…”

Section: Td-dft: Electronic Properties and Optical Spectramentioning

confidence: 99%

“…The twins are indistinguishable from most advanced face recognition techniques and even genetic analysis, yet they are not the same entities. Within the optical spectroscopy realm, an analogue of this 'twins problem' may arise from different carbon allotropes due to the alignment and correlations taking place between their optical signal transition frequencies [41][42][43] . An accurate description of the electronic and optical properties of carbynes and cyclo[n]carbons is valuable for a non-invasive, smart and rapid characterization of these sensitive 1D carbon allotropes, especially in a controlled synthesis environment.…”

Section: Introductionmentioning

confidence: 99%

Comparative Analysis of Absorption Resonances between Carbynes and Cyclo[n]carbons

Payod,

Pushkarchuk,

Michels

et al. 2023

Preprint

View full text Add to dashboard Cite

We present here two approaches to analyze the absorption resonances between carbynes and cyclo[n]carbons, namely the analytical tight-binding model to calculate the optical selection rules of cumulenic atomic rings and chains and the numerical time-dependent density functional theory for the optical investigation of polyynic carbon ring and chains. The optical absorption spectra of the carbon ring match that of the finite chain when their eigenenergies align following the Nring = 2Nchain+2 rule, which states that the number of atoms in an atomic ring Nring is twice the number of atoms on a finite chain Nchain with two additional atoms. We chose two representative atomic chains for our numerical calculations, specifically carbynes with N = 7 and 8 carbon atoms as a possible optical resonance spectra match to a recently synthesized carbon ring called cyclo[18]carbon. Despite the mismatch in resonance peaks, molecular orbital transitions of both carbynes N = 7 and 8 and cyclo[18]carbon reveal a wave function symmetry change from inversion to reflection and vice versa for allowed molecular orbital transitions which results in electron density redistribution along the polyynic carbyne axis or the cyclo[18]carbon circumference.

show abstract

2N+4-rule and an atlas of bulk optical resonances of zigzag graphene nanoribbons

Cited by 16 publications

References 67 publications

Unravelling the Complete Raman Response of Graphene Nanoribbons Discerning the Signature of Edge Passivation

Unravelling the Complete Raman Response of Graphene Nanoribbons Discerning the Signature of Edge Passivation

Polarization-dependent selection rules and optical spectrum atlas of twisted bilayer graphene quantum dots

Comparative Analysis of Absorption Resonances between Carbynes and Cyclo[n]carbons

Contact Info

Product

Resources

About