Related papers: Point defects on III-V semiconductor surfaces
We present first principles calculations of the electronic properties of trigonal selenium with emphasis on photovoltaic applications. The band gap and optical absorption spectrum of pristine selenium is calculated from many-body…
In the present Ph.D. Thesis we report an experimental investigation on the effects of gamma- and beta-ray irradiation and of subsequent thermal treatment on many types of a-SiO2 materials, differing in the production methods, OH- and…
We study the adsorption behavior of Ga on (0001) GaN surfaces combining experimental specular reflection high-energy electron diffraction with theoretical investigations in the framework of a kinetic model for adsorption and ab initio…
We have studied the driving forces governing reconstructions on polar GaN surfaces employing first-principles total-energy calculations. Our results reveal properties not observed for other semiconductors, as for example a strong tendency…
We investigate the electronic structure of the InAs/InP quantum dots using an atomistic pseudopotential method and compare them to those of the InAs/GaAs QDs. We show that even though the InAs/InP and InAs/GaAs dots have the same dot…
Functional properties of nanomaterials strongly depend on their surface atomic structure, but they often become largely different from their bulk structure, exhibiting surface reconstructions and relaxations. However, most of the surface…
The errors arising in ab initio density functional theory studies of semiconductor point defects using the supercell approximation are analyzed. It is demonstrated that a) the leading finite size errors are inverse linear and inverse cubic…
We present a first-principles study of the structural, electronic, and optical properties of hydrogenated amorphous silicon (a-Si:H). To this end, atomic configurations of a-Si:H with 72 and 576 atoms respectively are generated using…
The phenomenological boundary conditions for the envelope wave function, which is applicable for contacts of semiconductors with the rather different crystal symmetry are proposed. It is shown that the boundary conditions are determined by…
We report on a atomistic theory of electronic structure and optical properties of a single InAs quantum dot grown on InP patterned substrate. The spatial positioning of individual dots using InP nano-templates results in a quantum dot…
We report first-principles calculations that clarify the formation energies and charge transition levels of native point defects (Ga and O vacancies, interstitials, and a Ga vacancy-O vacancy pair) in corundum structured ${\alpha}$-Ga2O3.…
The core-level and valence band electronic structure of the well-defined near-surface layer of n-GaAs (100) has been studied by synchrotron-based high-resolution photoelectron spectroscopy before and after modification of the layer by an…
Small numbers of nitrogen dopants dramatically modify the electronic properties of GaAs, generating very large shifts in the conduction-band energies with nonlinear concentration dependence, and impurity-associated spatially-localized…
We investigate states on the surface of strong and weak topological insulators and superconductors that have been gapped by a symmetry breaking term. The surface of a strong 3D topological insulator gapped by a magnetic material is well…
Semiconductor coupled quantum dots provide a unique opportunity of tuning bandgaps by tailoring band offsets, making them ideal for photovoltaic and other applications. Here, we have studied stability, trends in the band gap, band offsets,…
The structural and electronic properties of interfaces between beta-SiC and III-V semiconductors are studied by first-principles calculations. Favorable bonding configurations are found to form between Si-V and C-III (model A) for BN, AlN,…
Lattice matched n-type AlInP(100) charge selective contacts are commonly grown on n-p GaInP(100) top absorbers in high-efficiency III-V multijunction solar or photoelectrochemical cells. The cell performance can be greatly limited by the…
We investigate geometric properties of surfaces given by certain formulae. In particular, we calculate the singular curvature and the limiting normal curvature of such surfaces along the set of singular points consisting of singular points…
In a common paradigm, the electronic structure of condensed matter is divided into weakly and strongly correlated compounds. While conventional band theory usually works well for the former class, many-body effects are essential for the…
The structural and electronic properties of gold decorated Si(335) surface are studied by means of density-functional calculations. The resulting structural model indicates that the Au atoms substitute some of the Si atoms in the middle of…