The large contact resistance is an insurmountable problem for the Schottky contact between the semiconducting two-dimensional channel material and the metal electrode. One solution to the Schottky contact issue is to decrease the contact resistance. Here, by using the first-principles calculations combined with the non-equilibrium Green’s function technique, we find that when monolayer arsenene is

X-ray emission spectroscopy (XES), as a complementary technique to x-ray absorption spectroscopy (XAS), is powerful in the analysis of the electronic structure of the materials by probing the occupied density of states with high energy resolution. Recently, an XES spectrometer optimized for the tender x-ray region (2–5 keV) was successfully installed into an inert atmosphere glovebox, and the entire

We introduce a design of a portable, multi-functional spectroscopic cell for in situ structural probe of materials using hard x-rays. This versatile reaction cell allows x-ray absorption fine structure (XAFS) and x-ray diffraction measurements in transmission mode on solids at a controlled temperature, pressure, and gas environment. A model heterogeneous catalysis system, co-aromatization of octane

We devise a mixing algorithm for full-potential (FP) all-electron calculations in the linearized augmented planewave (LAPW) method. Pulay’s direct inversion in the iterative subspace is complemented with the Kerker preconditioner and further improvements to achieve smooth convergence, avoiding charge sloshing and noise in the exchange–correlation potential. As the Kerker preconditioner was originally

A detailed understanding of interacting electrons in twisted bilayer graphene (tBLG) near the magic angle is required to gain insights into the physical origin of the observed broken symmetry phases. Here, we present extensive atomistic Hartree theory calculations of the electronic properties of tBLG in the (semi-)metallic phase as function of doping and twist angle. Specifically, we calculate quasiparticle

The electronic properties of hybrid organic–inorganic semiconductor interfaces depend strongly on the alignment of the electronic carrier levels in the organic/inorganic components. In the present work, we address this energy level alignment from first principles theory for two paradigmatic organic–inorganic semiconductor interfaces, the singlet fission materials tetracene and pentacene on H/Si(111)

The adsorption of molecules NH 3 , CH 4 , and H 2 O are studied on pristine and indium doped phosphorene (In@P). For adsorption, armchair (AC), zigzag, and isotropic/square supercells are used. We have calculated structural, adsorption energies and electronic properties using the first-principles method. The most stable configurations for adsorption on doped phosphorene are determined, and the adsorption

The perovskite oxides are known to be susceptible to structural distortions over a long wavelength when compared to their parent cubic structures. From an ab initio simulation perspective, this requires accurate calculations including many thousands of atoms; a task well beyond the remit of traditional plane wave-based density functional theory (DFT). We suggest that this void can be filled using the

Hafnium and zirconium mononitrides (HfN and ZrN) have been of interest for the hot carrier solar cell (HCSC) concept as a bulk absorber material and in thermoelectric power generation as a superlattice structure. Slowed hot carrier (HC) cooling is a fundamental requirement in an HCSC device because the carriers must be collected at high energy levels via energy selective contacts before they cool down

Structural, electronic and magnetic properties of four transition metal tri-chalcogenide monolayers—MnPS 3 , MnPSe 3 , FePS 3 and FePSe 3 —are studied using density functional theory. Lattice structures in good agreement with experiments are obtained. Electronic structure of the Mn compounds obtained using the PBE-GGA functional is in qualitative agreement with the experiments, apart from the well

Electron localisation descriptors, such as the electron localisation function (ELF) and localised orbital locator (LOL) provide a visual tool for interpreting the results of electronic structure calculations. The descriptors produce a quantum valence shell electron pair repulsion (VSEPR) representation, indicating the localisation of electron pairs into bonding pairs and lone pairs in single molecules

The major challenge of black phosphorus (BP) is its fast-oxidative degradation in air. Organic covalent chemical modification of BP flakes could suppress the chemical degradation. Here we focus on the effects of covalent chemical modification on the electronic structures of single layer BP. We employed the state-of-the-art first principles GW method, which is based on the many body green functions