Related papers: Hf defects in HfO2/Si
We have measured the far infrared reflectance of the heavy fermion compound URu$_2$Si$_2$ through the phase transition at T$_{HO}$=17.5 K dubbed 'hidden order' with light polarized along both the a- and c-axes of the tetragonal structure.…
Irradiation of graphene on SiO2 by 500 eV Ne and He ions creates defects that cause intervalley scattering as evident from a significant Raman D band intensity. The defect scattering gives a conductivity proportional to charge carrier…
In amorphous materials, acceptor and donor impurities rarely dope the system (shift the Fermi level). We find out why in a-Si:H. We report simulations on B and P doping of a-Si:H and a-Si. We analyze the Electronic Density of States (EDOS)…
We have investigated the properties of the $\beta$-Ga$_2$O$_3$($\bar201$)/HfO$_2$/Cr/Au MOS (metal-oxide-semiconductor) system after annealing (450$^\circ$C) in different ambient conditions (forming gas, N$_2$ and O$_2$). Defect properties…
In this paper we present detailed study of the density of states near defects in Bi$_2$Se$_3$. In particular, we present data on the commonly found triangular defects in this system. While we do not find any measurable quasiparticle…
A density functional study is presented of the interstitial Zn$_i$, Ge$_i$, and N$_i$ in ZnGeN$_2$. Corrections to the band gap are included by means of the LDA+U method. The Zn and Ge interstitials are both found to strongly prefer the…
Issues of Ge hut array formation and growth at low temperatures on the Ge/Si(001) wetting layer are discussed on the basis of explorations performed by high resolution STM and in-situ RHEED. Data of HRTEM studies of multilayer Ge/Si…
The effects of low carrier density and carrier compensation on mixed-state thermal transport are investigated beyond the quasiclassical approximation. It is shown that, contrary to the usual observations, the interplay of the two effects…
We investigate the effect due to background impurities embedded in the region of two-dimensional electron gases to the magnetotransport. These impurities are achieved by homogeneously incorporating Si atoms in single quantum wells of high…
The structural and electronic properties of amorphous silicon ($a$-Si) are investigated by first-principles calculations based on the density-functional theory (DFT), focusing on the intrinsic structural defects. By simulated melting and…
The electronic and optical properties of self-trapped holes in kappa-phase orthorhombic Ga2O3 in conjunction with isoelectronic and acceptor dopants were studied using hybrid density functional theory. Hole trapping was found to be…
Due to presence of magnetic field gradient needed for coherent spin control, dephasing of single-electron spin qubits in silicon quantum dots is often dominated by $1/f$ charge noise. We investigate theoretically fluctuations of ground…
We calculate correction to the critical temperature of a dirty superconductor, which results from the local variations of the gap function near impurity sites. This correction is of the order of T_c/E_F and becomes important for…
We use scanning tunneling microscopy (STM) to study magnetic Fe impurities intentionally doped into the high-temperature superconductor Bi$_{2}$Sr$_{2}$Ca$_{2}$CuO$_{8+\delta}$. Our spectroscopic measurements reveal that Fe impurities…
We present a microscopic investigation of frequently observed impurity-induced states in stoichiometric LiFeAs using low temperature scanning tunneling microscopy and spectroscopy (STM/STS). Our data reveal seven distinct well defined…
Properties of point defects resulting from the incorporation of inert-gas atoms in bcc tungsten are investigated systematically using first-principles density functional theory (DFT) calculations. The most stable configuration for the…
Isolated oxygen impurities and fully oxidized structures of four stable two-dimensional (2D) SiS structures are investigated by {\em ab initio} density functional calculations. Binding energies of oxygen impurities for all the four 2D SiS…
The electronic structure of interstitial hydrogen in a compound semiconductor FeS$_2$ (naturally $n$-type) is inferred from a muon study. An implanted muon (Mu, a pseudo-hydrogen) forms electronically different defect centers discerned by…
Absence of an efficient technology of GaAs passivation limits the use of III-V semiconductors in modern electronics. The effect reported here can possibly lead to a solution of this long standing problem. We found that an electrically…
We have studied the metallic behaviour in low density GaAs hole systems, and Si electron systems, close to the apparent two-dimensional metal-insulator transition. Two observations suggest a semi-classical origin for the metallic-like…