相关论文: First-principles study of defects and doping limit…
We present a model for typical charged defects in weakly doped Y1-xCaxVO3 perovskites and study how they influence the magnetic and orbital order. Starting from a multiband Hubbard model, we show that the charge carriers introduced by…
Ceria (CeO$_2$) is a material of significant technological importance. A detailed understanding of the material's defect physics and chemistry is key to understanding and optimizing its properties. Here, we report a hybrid…
Point defects in Ga- and Al-doped ZnO thin films are studied by means of first principles electronic structure calculations. Candidate defects are identified to explain recently observed differences in electrical and spectroscopical…
We apply hybrid density functional theory calculations to identify the formation energies and thermodynamic charge transition levels of native point defects, common impurities, and shallow dopants in BAs. We find that boron-related defects…
A microscopic theory is presented for the observed electronic disorder in superconducting Bi$_2$Sr$_2$CaCu$_2$O$_{8+\delta}$. The essential phenomenology is shown to be consistent with the existence of two types of interstitial oxygen…
We use hybrid density functional calculations to assess n-type doping in monoclinic (Al$_x$Ga$_{1-x}$)$_2$O$_3$ alloys. We focus on Si, the most promising donor dopant, and study the structural properties, formation energies and…
The modification of the properties of CeO$_2$ through aliovalent doping are investigated within the \emph{ab-initio} density functional theory framework. Lattice parameters, dopant atomic radii, bulk moduli and thermal expansion…
In light of the recent discovery of giant electrostriction in defective fluorites, here we investigate the interplay between mechanical, electrochemical and electromechanical properties of oxygen defective ceria compositions as the effect…
The critical doping levels in cuprates, where the ground state changes its nature (from an antiferromagnet to a spin glass to superconductor to metal), are not universal. We investigate the origin of these critical doping variations by…
The interplay between superconductivity and charge-density wave (CDW) order, and its evolution with carrier density, is central to the physics of many quantum materials, notably high-$T_c$ cuprates and kagome metals. Hole-doped kagome…
Hydrogenated amorphous silicon is well known for its various alloys and wide ranging opto-electronic properties. Hydrogenated silicon sub-oxide (aSiO:H) is one of them. The effect of boron doping on optoelectronic properties of the aSiO:H…
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…
We discuss the applicability of the pseudopotential-like self-interaction correction (pSIC) to the study of defect energetics and electronic structure of In2O3. Our results predict that substitutional (at oxygen sites) and interstitial (at…
Zirconia (ZrO2) is an important material with technological applications which are affected by point defect physics. Ab-initio calculations are performed to understand the structural and electronic properties of oxygen vacancies and…
We present local structural evidence for the existence of charge inhomogeneities at low temperature in underdoped and optimally doped La_2-xSr_xCuO_4. The inhomogeneities disappear for x > 0.2. The evidence for the charge inhomogeneities…
We report first-principles microscopic calculations of the formation energy, electrical activity, and magnetic moment of Co dopants and a variety of native defects in TiO2 anatase. Using these results, we use equilibrium thermodynamics to…
Employing strong electrostatic gating (liquid-ion gating), the position of the Fermi energy E_F (relative to the charge-neutrality point) was determined in multi-wall carbon nanotubes (MWNTs). E_F is negative (hole doping) and amounts to…
Doping of La_2CuO_4 and La_{1.6}Nd_{0.4}CuO_4 with Sr gives rise to holes that locate pairwise at lattice-site O atoms. Such O atoms reside as lattice defects in the CuO_2 planes if the doping level x is below a watershed value, x < x^, but…
Different dopants with their specific dopant concentration can be utilized to produce ferroelectric HfO$_2$ thin films. In this work it is explored for the example of Sr in a comprehensive first-principles study. Density functional…
We investigate the origin of superconductivity in doped SrTiO$_3$ (STO) using a combination of density functional and strong coupling theories within the framework of quantum criticality. Our density functional calculations of the…