Optical excitations of graphene-like materials: group III-nitrides

Abstract

By using first-principles calculations, we have studied the electronic and optical characteristics of group III-nitrides, such as BN, AlN, GaN, and InN monolayers. The optimized geometry, quasi-particle energy spectra, charge...

Electronic, magnetic, and optical properties of Np and Pu decorated armchair graphene nanoribbons: a DFT study

“…The highest occupied valence states and the lowest unoccupied conduction ones, which account for a band gap, respectively arise from p z and (p x , p y ) orbitals, in which the latter is associated with the carbon edge-atoms. This result differs from those observed in single-layer 40 and few-layer graphene systems, 41 graphene-like materials 16 and d-IV-VI monolayers, 12 where the electronic and hole states arise from p z and p z orbitals, as well as p x (p y ) and p y (p x ) orbitals, respectively. Aer being passivated by the hydrogen atoms, the low-lying conduction structures are only dominated by the 2p z orbitals (Fig.…”

“…The electronic properties of graphene give rise to numerous remarkable characteristics, such as high carrier mobility at 300 K (>200 000 cm 2 V −1 s −1 ), 4 superior thermo-conductivity (3000-5000 W m −1 K −1 ), 5 extremely high modulus (∼11 TPa) 6 and tensile strength (∼1100 GPa), 7 high transparency to incident light over a broad range of wavelengths (97.7%), 8 and an anomalous quantum Hall effect. 9 Since then, much research on graphene and other 2D graphene-like materials [10][11][12][13][14][15][16][17][18][19][20] has captured the attention of experimental and theoretical researchers, spanning the realms of fundamental science and applied technology. 21 Particularly, considerable research interest has centered on one-dimensional (1D) graphene nanoribbons (GNRs), primarily due to their distinctive honeycomb lattice structure and the intriguing effects of nite-size quantum connement.…”

Density Functional Theory Study of AlN Nanosheets with Biphenylene Structure: Stability, Electronic, Thermoelectric, Mechanical, and Optical Properties

“…The highest optical mode calculated for this layer is 32 THz, surpassing those of honeycomb lattice AlN, GaN, and InN monolayers. 46 Furthermore, as illustrated in Figure 2a, the phonon frequencies are divided into two regions (high and low) separated by a phonon gap of 7.03 THz.…”

“…This comprehensive breakdown provides a nuanced understanding of the supercell’s vibrational behavior, highlighting the intricate interplay between its various phonon modes. The highest optical mode calculated for this layer is 32 THz, surpassing those of honeycomb lattice AlN, GaN, and InN monolayers . Furthermore, as illustrated in Figure a, the phonon frequencies are divided into two regions (high and low) separated by a phonon gap of 7.03 THz.…”