The correlation between sub-band gap absorption and the chemical states and electronic and atomic structures of S-hyperdoped Si have been extensively studied, using synchrotron-based x-ray photoelectron spectroscopy (XPS), x-ray absorption near-edge spectroscopy (XANES), extended x-ray absorption fine structure (EXAFS), valence-band photoemission spectroscopy (VB-PES) and first-principles calcu...

Two-dimensional (2D) hexagonal organometallic framework (HOMF) made of triphenyl-metal molecules bridged by metal atoms has been recently shown to exhibit exotic electronic properties, such as half-metallic and topological insulating states. Here, using first-principles calculations, we investigate systematically the structural, electronic, and magnetic properties of such HOMFs containing 3d tr...

Local curvature, or bending, of a graphene sheet is known to increase the chemical reactivity presenting an opportunity for templated chemical functionalisation. Using first-principles calculations based on density functional theory (DFT), we investigate the reaction barrier reduction for the adsorption of atomic hydrogen at linear bends in graphene. We find a significant barrier lowering (≈15%...

Polar and nonpolar ZnO thin films were deposited on MgO (001) substrates under different deposition parameters using oxygen plasma-assisted molecular beam epitaxy (MBE). The orientations of ZnO thin films were investigated by in situ reflection high-energy electron diffraction and ex situ X-ray diffraction (XRD). The film roughness measured by atomic force microscopy evolved as a function of su...

A high-resolution angle-resolved photoemission spectroscopy (ARPES) study of Fe(110) single crystal was conducted to elucidate many-body interactions between quasi-particles at the Fermi level at low temperature. Two kink structures were observed in the energy-band dispersion at the binding energies of ~40 meV and ~270 meV for the bulk-derived band on the majority-spin Fermi surface around the ...

We report on ab initio calculations of electronic states of two large and realistic models of amorphous silicon generated using a modified version of the Wooten-Winer-Weaire algorithm and relaxed, in both cases, with a Keating and a modified Stillinger-Weber potentials. The models have no coordination defects and a very narrow bond-angle distribution. We compute the electronic density-of-states...

Layered transition-metal dichalcogenides have emerged as exciting material systems with atomically thin geometries and unique electronic properties. Pressure is a powerful tool for continuously tuning their crystal and electronic structures away from the pristine states. Here, we systematically investigated the pressurized behavior of MoSe2 up to ∼ 60 GPa using multiple experimental techniques ...

We used first-principle simulation methods to generate amorphous TiO2 (a-TiO2) models and obtained chemically-ordered amorphous networks. We analyzed the structural and the electronic properties of the resulting computationally generated structures. We propose that two peaks found in the Ti-Ti pair correlation correspond to the edge-sharing and the corner-sharing Ti-Ti pairs. Resulting coordina...

The application of machine learning (ML) to electronic structure theory enables property prediction with ab initio accuracy. However, most previous ML models predict one or several properties intrinsic materials. band structure, which embeds all the main information, has yet be deeply studied. This is a challenging task due highly variable inputs and outputs; input materials may have different ...

The absorption properties in hetero-polarization GaN/AlxGa1 xN (x 1⁄4 0:06) quantum well structures are studied in reflection, photoreflection, and photoluminescence excitation spectroscopy and compared with the results of band structure calculations. Above the energy of the main luminescence transitions we observe three distinct absorption thresholds. From Franz-Keldysh oscillations in the abs...