相关论文: Annealing of radiation induced defects in silicon …
Optically active spin defects in solids are promising platforms for quantum technologies. Here, we present a first-principles framework to investigate intersystem crossing processes, which represent crucial steps in the optical…
Dispersion relations and amplitudes of collective pionic modes are derived in a pi + nucleon-hole + delta-hole model for use in transport descriptions by means of a local density approximation. It is discussed how pionic modes can be…
Disorder-driven degradation phenomena, such as structural phase transformations and surface reconstructions, can significantly reduce the lifetime of Li-ion batteries, especially those with nickel-rich layered-oxide cathodes. We develop a…
Optically addressable spin defects in silicon carbide, including the neutral divacancy (VV$^0$) and the negative nitrogen-vacancy (NV$^-$), are among leading building blocks of solid-state quantum technologies. Integrating these defects…
Using first principles calculations we have studied the formation energies, electron and hole affinities, and electronic levels of intrinsic point defects in zircon. The atomic structures of charged interstitials, vacancies, Frenkel pairs…
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…
Kink defects in the 90-degree partial dislocation in silicon are studied using a linear-scaling density-matrix technique. The asymmetric core reconstruction plays a crucial role, generating at least four distinct kink species as well as…
Continuum-buried defect states in semiconductors are generally expected to be optically inactive due to their strong coupling to continuum bands. Here, we show that such defects can instead host radiative electronic bound states in the…
We obtain a system of exact solutions of the Dirac equation for an electron moving in a constant homogeneous external magnetic field with account of its vacuum magnetic moment and assumed Lorentz invariance violation in the minimal CPT-odd…
The acceptor removal phenomenon (ARP), which hampers the functionality of low-gain avalanche detectors (LGAD), is discussed in frame of the A_Si-Si_i-defect model. The assumption of fast diffusion of interstitial silicon is shown to be…
The problem of the low-energy highly-anharmonic quantum dynamics of isolated impurities in solids is addressed by using path-integral Monte Carlo simulations. Interstitial oxygen in silicon is studied as a prototypical example showing such…
Silicon is the most important semiconductor electrode with applications in photoelectrochemistry and sensor technology. Yet its electrochemistry exhibits many poorly understood phenomena, including oscillations during the anodic dissolution…
Defects ~10 nm in size, with number densities ~10^{10} cm^{-2}, form spontaneously beneath ion-milled, etched, or HF-dipped silicon surfaces examined in our Ti-ion getter-pumped transmission electron microscope (TEM) after exposure to air.…
We report a first-principles study of vacancy-induced self-diffusion in crystalline silicon. Starting form a fully relaxed configuration with a neutral vacancy, we proceed to search for local diffusion paths. The diffusion of the vacancy…
The nature and interplay of intrinsic point and extended defects in n-type Si-doped InN epilayers with free carrier concentrations up to 6.6x10E20cm-3 are studied using positron annihilation spectroscopy and transmission electron microscopy…
The dynamics of amorphous silicon at low temperatures can be characterized by a sequence of discrete activated events, through which the topological network is locally reorganized. Using the activation-relaxation technique, we create more…
Defect charge-state dynamics are central to both spin-photon interfaces and photoelectrical spin readout. Despite the significance of silicon vacancies (V1/V2) in silicon carbide (4H-SiC) for both applications, their ionization behavior has…
The carbon vacancy in $4H$-SiC is a powerful minority carrier recombination center and a major cause of degradation of SiC-based devices. Despite the extensiveness of the literature regarding the characterization and modeling of the defect,…
Single-photon transitions are one of the key technologies for designing and operating very-long-baseline atom interferometers tailored for terrestrial gravitational-wave and dark-matter detection. Since such setups aim at the detection of…
Solid-state defect quantum systems are exquisite probes of their local charge environment. Nonlinear dynamical electric fields in solids are challenging to characterize directly, conventionally limited to coarse macroscopic methods which…