Related papers: Excitonic complexes in anisotropic atomically thin…
A three-dimensional weak coupling BCS model with an {\it anisotropic} pairing interaction in momentum space is reported. It exhibits an anisotropic gap in accord with recent experimental observations for high-$T_c$ oxides. The gap ratio ${2…
On the basis of many-body {\it ab-initio} calculations, using single-shot G$_0$W$_0$ method and Bethe-Salpeter equation, we study phosphorene nanoribbons (PNRs) in the two typical zigzag and armchair directions. The electronic structure,…
Two-dimensional (2D) layered materials emerge in recent years as a new platform to host novel electronic, optical or excitonic physics and develop unprecedented nanoelectronic and energy applications. By definition, these materials are…
As an emerging single elemental layered material with a low symmetry in-plane crystal lattice, black phosphorus (BP) has attracted significant research interest owing to its unique electronic and optoelectronic properties, including its…
Anisotropy of light-matter interactions in materials give remarkable information about the phonons and their interactions with electrons. We report the angle-resolved polarized Raman spectroscopy of single-crystal of Bi2Se3 to obtain the…
We show that the optical absorption spectra of boron nitride (BN) nanotubes are dominated by strongly bound excitons. Our first-principles calculations indicate that the binding energy for the first and dominant excitonic peak depends…
We report calculations of the energies of excitons and biexcitons in ideal two-dimensional bilayer systems within the effective-mass approximation with isotropic electron and hole masses. The exciton energies are obtained by a simple…
The interplay between dimensionality and anisotropicity leads to intriguing optoelectronic properties and exciton dynamics in low dimensional semiconductors. In this study we use nanostructured phosphorene as a prototypical example to…
Besides the chemical constituents, it is the lattice geometry that controls the most important material properties. In many interesting compounds, the arrangement of elements leads to pronounced anisotropies, which reflect into a varying…
We have used magneto-photoluminescence measurements to establish that InP/GaAs quantum dots have a type-II (staggered) band alignment. The average excitonic Bohr radius and the binding energy are estimated to be 15nm and 1.5 meV…
We examine the electronic properties of 2D electron gas in black phosphorus multilayers in the presence of a perpendicular magnetic field, highlighting the role of in-plane anisotropy on various experimental quantities such as ac…
High-performance infrared photodetection underpins various applications spanning surveillance, environmental monitoring, optical communications and biomedical imaging. However, conventional bulk detectors remain limited by poor spectral…
Two-dimensional materials and their heterostructures have emerged as a new class of materials for not only fundamental physics but also for electronic and optoelectronic applications. Black phosphorus (BP) is a relatively new addition to…
Optical and electronic properties of black phosphorus strongly depend on the number of layers and type of stacking. Using first-principles calculations within the framework of density functional theory, we investigate the electronic…
Anisotropic two-dimensional layered materials with low-symmetric lattices have attracted increasing attention due to their unique orientation-dependent mechanical properties. Black arsenic (b-As), with the puckered structure, exhibits…
We study the stability and electronic structure of previously unexplored two-dimensional (2D) ternary compounds BNP$_2$ and C$_2$SiS. Using $ab$ $initio$ density functional theory, we have identified four stable allotropes of each ternary…
Raman scattering and photoluminescence spectroscopy are used to investigate the optical properties of single layer black phosphorus obtained by mechanical exfoliation of bulk crystals under an argon atmosphere. The Raman spectroscopy,…
On the basis of detailed ab initio studies the influence of strain on the anisotropy of the transport distribution of the thermoelectrics Bi$_2$Te$_3$ and Sb$_2$Te$_3$ was investigated. Both tellurides were studied in their own, as well as…
Exciton effects are studied in single-wall boron-nitride nanotubes. The Coulomb interaction dependence of the band gap, the optical gap, and the binding energy of excitons are discussed. The optical gap of the (5,0) nanotube is about 6eV at…
New allotropes of two-dimensional (2D) GaP and InP binary compounds were predicted from the structural optimization and dynamical stability analysis in the framework of the density functional calculations. These stabilized GaP and InP…