Related papers: Self-compensation due to point defects in Mg-doped…
We report the results of an ab initio modeling of substitutional impurities such as zinc, copper and zirconium ions incorporated into the magnesium sublattice of MgB2. The goal of computational studies was to gain an atomistic understanding…
Infrared spectroscopic ellipsometry is applied to investigate the free-charge carrier properties of Mg-doped InN films. Two representative sets of In-polar InN grown by molecular beam epitaxy with Mg concentrations ranging from…
A compact analytical model is developed for the mobile charge density of polar multiple channel field effect transistors. Two dimensional electron and hole gases can be potentially induced by spontaneous and piezoelectric polarization in…
The band structure of a prototypical dilute ferromagnetic semiconductor, Ga$_{1-x}$Mn$_{x}$As, is studied across the phase diagram via optical spectroscopy. We prove that the Fermi energy ($E_{F}$) resides in a Mn induced impurity band…
Hybrid functionals and empirical correction schemes are compared to conventional semi-local density functional theory (DFT) calculations in order to assess the predictive power of these methods concerning the formation energy and the charge…
Erbium (Er) doped GaN has been studied extensively for optoelectronic applications, yet its defect physics is still not well understood. In this work, we report a first-principles hybrid density functional study of the structure,…
We use a combination of ab initio calculations and statistical mechanics to investigate the substitution of Li+ for Mg2+ in magnesium hydride (MgH2) accompanied by the formation of hydrogen vacancies with positive charge (with respect to…
We consider a mean-field approach to the hole-mediated ferromagnetism in III-V Mn-based semiconductor compounds to discuss the dependence of the hole density on that of Mn sites in Ga_{1-x}Mn_xAs. The hole concentration, p, as a function of…
A systematic study of hole compensation effect on magnetic properties, which is controlled by defect compensation through ion irradiation, in (Ga,Mn)As, (In,Mn)As and (Ga,Mn)P is presented in this work. In all materials, both Curie…
(Al$_x$Ga$_{1{\rm -}x})_2$O$_3$ alloys are frequently used in heterostructures with monoclinic Ga$_2$O$_3$, resulting in a large conduction-band offset, which leads to charge carrier confinement, a property that is desirable for device…
Realistic oxide materials are often semiconductors, in particular at elevated temperatures, and their surfaces contain undercoordiated atoms at structural defects such as steps and corners. Using hybrid density-functional theory and ab…
The realization of $p$-type doping in wide-band-gap oxide semiconductors remains a major challenge, particularly in $\beta-Ga_2O_3$ where nitrogen has long been considered a potential acceptor dopant but has consistently failed to produce…
First-principles calculations are employed to explore avenues to increase the N\'eel temperature ($T_{\mathrm{N}}$) of the magnetoelectric antiferromagnet Cr$_2$O$_3$ through doping. Employing the hybrid functional method, we calculate the…
We adapt the Goldstone theorem to study spontaneous symmetry breaking in relativistic theo- ries at finite charge density. It is customary to treat systems at finite density via non-relativistic Hamiltonians. Here we highlight the…
The future of spintronic and semiconductor applications demands materials with tailored electronic and magnetic properties. This study uses density functional theory to investigate the electronic structure of the half-metallic compound…
The interplay between disorder and spin polarization in a GaMnAs thin layer results into spin-polarized impurity hole bands. A figure of merit is defined to label the hole state as being extended or localized. The calculation leads to a…
In materials science, point defects play a crucial role in materials properties. This is particularly well known for the wide band gap insulators where the defect formation/compensation determines the equilibrium Fermi level and generally…
Ga2O3 is being actively explored for high-power and high-temperature electronics, deep-ultraviolet optoelectronics, and other applications. Efficient n-type doping of Ga2O3 has been achieved, but p-type doping faces fundamental obstacles…
A generalized antiferromagnetic approach to the Mott transition is analyzed with special emphasis on electron doped cuprates, where evidence for electronic phase separation is weak or absent. Fluctuations are incorporated via a…
In many semiconductors, compensating defects set doping limits, decrease carrier mobility, and reduce minority carrier lifetime thus limiting their utility in devices. Native defects are responsible in many cases, but extrinsic dopants may…