相关论文: Hf defects in HfO2/Si

In a recent Letter Scanlon and Watson reported their first principles results on hydrogen in Cu2O. Their main conclusions are: (1) an interstitial H in Cu2O prefers to occupy the tetrahedral site, which is coordinated with four Cu cations,…

Controlling the contamination of silicon materials by iron, especially dissolved interstitial iron (Fe$_{\mathrm{i}}$), is a longstanding problem with recent developments and several open issues. Among these we have the question whether…

We perform hybrid-density functional calculations to investigate the charged defect formation energy of native point defects in $Mg_2 Si$, $Mg_2 Sn$, and their solid solutions. The band gap correction by hybrid-density functional is found…

A study based on density functional theory calculations was performed for the three charge states of interstitial hydrogen in Yttria. The present calculations were carried out by employing the GGA-PBE and the HSE06 exchange-correlation…

We study backscattering of electrons and conductance suppression in a helical edge channel in two-dimensional topological insulators with broken axial spin symmetry in the presence of nonmagnetic point defects that create bound states. In…

We study selected transition metal related point defects in silicon and silicon carbide semiconductors by a range separated hybrid density functional (HSE06). We find that HSE06 does not fulfill the generalized Koopmans' Theorem for every…

The formation energies of the oxygen vacancy and titanium interstitial in rutile TiO2 were calculated by the screened exchange (sX) hybrid density functional method, which gives a band gap of 3.1 eV, close to the experimental value. The O…

Materials with good carrier mobilities are desired for device applications, but in real devices the mobilities are usually limited by the presence of interfaces and contacts. Mobility degradation at semiconductor-dielectric interfaces is…

Using the non-equilibrium Keldysh Green's function formalism, we investigate the effect of defects on the electronic structure and transport properties of two-dimensional topological insulators (TI). We demonstrate how the spatial flow of…

We present a first-principle study of geometrical and electronic structure of hexagonal single-walled silicon nanotubes with a monovacancy or a substitutional defect. The C, Al or P atoms are chosen as substitutional impurities. It is found…

We study coherent backscattering phenomena from single and multiple stacking faults (SFs) in 3C- and 4H-SiC within density functional theory quantum transport calculations. We show that SFs give rise to highly dispersive bands within both…

In the present theoretical work we have considered impurities, either boron or phosphorous, located at different substitutional sites in silicon quantum dots (Si-QDs) with diameters around 1.5\,nm, embedded in a SiO2 matrix. Formation…

The influence of individual impurities of Fe on the electronic properties of topological insulator Bi$_2$Se$_3$ is studied by Scanning Tunneling Microscopy. The microscope tip is used in order to remotely charge/discharge Fe impurities. The…

We study in detail by means of ab-initio pseudopotential calculations the electronic structure of five-fold coordinated (T_5) defects in a-Si and a-Si:H, also during their formation and their evolution upon hydrogenation. The atom-projected…

To resolve the microscopic origin of magnetism in the Fe2O3/FeTiO3-system, we have performed density functional theory calculations taking into account on-site Coulomb repulsion. By varying systematically the concentration, distribution and…

Spin qubits in Silicon quantum dots can have long coherence times, yet their manipulation relies on the exchange interaction, through which charge noise can induce decoherence. Charge traps near the interface of a Si heterostructure lead to…

Point defects may introduce defect levels into the fundamental band gap of the host semiconductors that alter the electrical properties of the material. As a consequence, the in-gap defect levels and states automatically lower the threshold…

High frequency (hf) conductivity in the form $\sigma^{hf} = \sigma_1^{hf} - i\sigma_2^{hf}$ was obtained from the measurement of Surface Acoustic Waves (SAW) attenuation and velocity (f=30 MHz) in GaAs/AlGaAs heterostructures ($n=1.3-7\cdot…

Native point defects, defect complexes, and oxygen impurities in BaCuChF were studied using density functional theory calculations, self-consistent thermodynamic simulations, and various experimental techniques. Unintentional p-type…

Half-metallic ferromagnets and especially the full-Heusler alloys containing Co are at the center of scientific research due to their potential applications in spintronics. For realistic devices it is important to control accurately the…