Electronic and optical properties of graphene, silicene, germanene, and their semi-hydrogenated systems

Abstract

We investigate the geometric, electric, and optical properties of two-dimensional honeycomb lattices using first-principles simulations.

Theoretical investigations of the electronic and optical properties of a GaGeTe monolayer

“…Our ndings can facilitate a better understanding of various phenomena and multiple applications of monolayer GaGeTe, using the developed theoretical framework which was successfully published in previous studies. [26][27][28][29][30]…”

2D Ge2Se2P4 Monolayer: A Versatile Photocatalyst for Sustainable Water Splitting

“…The optical properties could be comprehended through the dielectric functions, which are represented by ε(ω) = ε 1 (ω) + i ε 2 (ω). In which, the imaginary part of dielectric functions is related to the excitation of electrons from the occupied states | vk ⟩ to the unoccupied ones | ck ⟩ and can be achieved through Fermi’s golden rule ε 2 ( ω ) ∝ ∑ v c k false| ⟨ v k | ê · p | c k ⟩ false| 2 δ ( ω − E c k − E v k ) where the oscillation strength and the transition energy of the absorbance spectrum, correspondingly, are directly related to the square of the velocity matrix element false| ⟨ v k | ê · p | c k ⟩ false| 2 and the electronic joint density of states δ(ω– E ck – E vk ). The real part ε 1 (ω) is then obtained via the Kramers–Kronig relations …”

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

“…The B–N, Al–N, Ga–N, and In–N bond lengths are equal to 1.45 Å, 1.81 Å, 1.88 Å, and 2.10 Å, respectively, which agree well with previous studies. 10,63 Similar to that of graphene, 64 group III–V honeycomb lattices are constructed by the rather strong impure σ bonding, while the impure π bonds due to the impure p z orbital hybridizations are rather weak and well separated from the σ ones. Even though they have a similar structure, the electronic and optical properties of group III–V materials are predicted to be rather different from that of graphene due to the presence of impure orbital hybridizations, and the broken hexagon symmetry.…”