Reconfigurability of photonic integrated circuits (PICs) has become increasingly important due to the growing demands for electronic-photonic systems on a chip driven by emerging applications, including neuromorphic computing, quantum information, and microwave photonics. Success in these fields usually requires highly scalable switching units as essential building blocks. Current switches, however, mainly rely materials with weak, volatile thermo-optic or electro-optic modulation effects,...

In this Letter we investigate boron diffusion as a function of the Fermi-level position in crystalline silicon using ab initio calculations. Based on our results, new mechanism for B mediated by Si self-interstitials is proposed. Rather than kick out into mobile channel, find direct boron-interstitial pair all positions. Our activation energy $3.5--3.8$ eV, migration barrier $0.4--0.7$ and diffusion-length exponent $\ensuremath{-}0.6$ to $\ensuremath{-}0.2$ eV are excellent agreement with experiment.

Single‐phase monoclinic aluminum–gallium oxide powders, β−(Al x Ga 1− ) 2 O 3 , have been produced by solution combustion synthesis for Al fraction 0 ≤ < 0.8. α−(Al is observed = 1, with mixed α + β The contraction in lattice parameters and increase band gap increasing concentration were characterized X‐ray diffraction ( XRD photoelectron spectroscopy XPS ), respectively, are compared a first‐principles density‐functional theory calculation. A novel filtering procedure described to reduce...

Progress in integrated nanophotonics has enabled large-scale programmable photonic circuits (PICs) for general-purpose electronic-photonic systems on a chip. Relying the weak, volatile thermo-optic or electro-optic effects, such usually exhibit limited reconfigurability along with high energy consumption and large footprints. These challenges can be addressed by resorting to chalcogenide phase-change materials (PCMs) as Ge2Sb2Te5 (GST) that provide substantial optical contrast self-holding...

Surface band bending and surface defects on the UV-transparent conducting oxide β-Ga2O3 (100) are studied with hard x-ray photoemission spectroscopy scanning tunneling microscopy. Highly doped shows flat bands near surface, while nominally undoped (but still n-type), air-cleaved bent upwards by ≳0.5 eV. Negatively charged observed vacuum annealed β-Ga2O3, which also upward bending. Density functional calculations show oxygen vacancies not likely to be ionized in bulk, but could activated The...

We develop a framework powered by machine learning (ML) and high-throughput density functional theory (DFT) computations for the prediction screening of impurities in groups IV, III-V, II-VI zinc blende semiconductors. Elements spanning length breadth periodic table are considered as impurity atoms at cation, anion, or interstitial sites supercells 34 candidate semiconductors, leading to chemical space approximately 12,000 points, 10% which used generate DFT dataset charge dependent defect...

In this paper, we consider how oxidation in dry O2 influences the point-defect densities silicon. By using relationships based on continuity equations oxide and applying a proposed set of boundary conditions to oxidizing Si-SiO2 system, derive an analytic expression for supersaturation interstitials during oxidation. The analysis results having experimentally observed sublinear dependence rate without requiring any assumptions nonlinearity. addition, through observations linear constant...

We present quantum-based simulations of single grain boundary reflectivity electrons in metals, Cu and Ag. examine twin non-twin boundaries using non-equilibrium Green's function first principles methods. also investigate the mechanism by modeling atomic vacancies, disorder, orientation find that change disorder itself both contribute significantly to reflectivity. may vary widely depending on structure consistent with experimental results. Finally, we from multiple depend neighboring...

Manganese(II)-doped cesium–lead–chloride (Mn2+:CsPbCl3) perovskite nanocrystals have recently been developed as promising luminescent materials and attractive candidates for white-light generation. One approach to tuning the luminescence of these has involved anion exchange incorporate Br–, but effects on Mn2+ speciation in doped metal-halide perovskites is not well understood at a microscopic level. Here, we use combination X-band electron paramagnetic resonance (EPR) photoluminescence...

CsPb(Cl1–xBrx)3 (0 ≤ x 1) nanocrystals and thin films doped with a series of trivalent rare-earth ions (RE3+ = Y3+, La3+, Ce3+, Gd3+, Er3+, Lu3+) have been prepared studied using variable-temperature time-resolved photoluminescence spectroscopies. We demonstrate that aliovalent (trivalent) doping this type universally generates new often-emissive defect state ca. 50 meV inside the perovskite band gap, independent specific RE3+ dopant identity or form (nanocrystals vs films)....

Point defects directly impact solar cell device performance by limiting the carrier lifetime. In this work, density functional theory calculations are first used to determine formation energy and diffusion barriers of dominant in Cu(In,Ga)Se <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> . Next, continuum reaction–diffusion models developed analyze redistribution during manufacturing processes. We estimate defect capture cross sections...

Vacancy-mediated diffusion of dopants in silicon is investigated using Monte Carlo simulations hopping diffusion, as well analytic approximations based on atomistic considerations. Dopant/vacancy interaction potentials are assumed to extend out third-nearest neighbor distances, required for pair theories. Analysis focusing the sites bridging configurations uncorrelated hops leads an improved model vacancy-mediated dopant diffusion. The vacancy motion a doped lattice verify results moderate...

Single crystals of transition metal (TM) doped β–Ga2O3, a wide gap semiconductor system interest for transparent conductive oxide and diluted magnetic applications, have been studied in the dilute, non-interacting limit (≤0.06 cation %). Based on optical absorption, particle induced x-ray emission, Rutherford backscattering measurements, Mn does not incorporate as well Cr, degrades crystal quality. Using superconducting quantum interference device (SQuID) magnetometry, Brillouin type...

Ion exchange, in which an in-diffusing ion replaces a lattice ion, has been widely exploited as synthetic tool for semiconductor doping and solid-to-solid chemical transformations, both bulk at the nanoscale. Here, we present systematic investigation of cation-exchange reactions that involve displacement Mn2+ from CdSe nanocrystals by Cd2+ or In3+. For incoming cations, is spontaneous but thermally activated, following Arrhenius behavior over broad experimental temperature range. At any...

Knowledge of the nitrogen-vacancy center formation kinetics in diamond is critical to engineering sensors and quantum information devices based on this defect. Here we utilize longitudinal tracking single NV centers elucidate defect during high-temperature annealing from 800-1100 $^\circ$C high-purity chemical-vapor-deposition diamond. We observe three phenomena which can coexist: formation, quenching, orientation changes. Of relevance NV-based applications, a 6 24-fold enhancement density,...

Interactions of point defects with SiO2 films play a central role in integrated circuit fabrication processes. In this work, model is developed for the Si-SiO2 system that considers segregation excess silicon between oxide and substrate diffusion reaction SiO2. The able to explain broad range experimental observations under both oxidizing nonoxidizing conditions consistent manner including: variation interstitial supersaturation oxidation rate steam dry O2 ambients, enhanced retarded results...

In this paper, we develop and analyze models for the coupled diffusion of dopants point defects, since such have been observed to display qualitative aspects high concentration phosphorus profiles as characteristic "kink tail." We begin by describing a general model via dopant/defect pairs assuming local equilibrium electronic processes, but not chemical processes. Using system, along with parameters based on experimental data previously reported in literature, test common assumptions. Our...

In the companion paper [J. Appl. Phys. 59, 2541 (1986)], we developed a model based on continuity equation approach for supersaturation of interstitials during oxidation in dry O2. The analysis resulted an expression having experimentally observed sublinear dependence rate without requiring any assumptions nonlinearity. Through observations linear constant at linear-parabolic ambient oxygen pressure, predictions were made how interstitial will vary with given temperature. this paper, those...

In this work, we develop models for the gettering of metals in silicon by high phosphorus concentration. We first performed ab initio calculations to determine favorable configurations complexes involving and transition (Fe, Cu, Cr, Ni, Ti, Mo, W). Our found that P4V cluster, a vacancy surrounded 4 nearest-neighbor atoms, which is most inactive P species heavily doped Si, strongly binds such as Fe. Based on calculated binding energies, build continuum describe deactivation Fe processes with...

The nitrogen vacancy (NV) center in diamond is a sensitive probe of magnetic field and promising qubit candidate for quantum information processing. performance many NV-based devices improves by aligning the NV(s) parallel to single crystallographic direction. Using ab initio theoretical techniques, we show that NV orientation can be controlled high-temperature annealing presence strain under currently accessible experimental conditions. We find $(89\pm7)\%$ NVs align along [111] direction...

The silicon point defect properties which control the spatial extent of their interactions (e.g., interstitial diffusivity) have been calculated by many researchers. However, large discrepancies exist in reported values these parameters, and it is essential to a consistent set parameters for use process simulation. To meet this need, we present here model includes important ignored previous analyses, specifically bulk recombination interstitials with vacancies segregation surface oxide...

Implanted fluorine is observed to behave unusually in silicon, manifesting apparent uphill diffusion and reducing enhancing activation of boron. In order investigate behavior, we calculate the energy defect structures framework density functional theory. addition identifying ground-state configuration migration barrier a single atom set energetically favorable were found (F(n)V(m)). The decoration vacancies dangling silicon bonds by suggests that accumulates vacancy-rich regions, which...

We present a general theory of stress effects on the solid solubility impurities in crystalline materials, including ionization and Fermi level semiconductors. Critical errors limitations previously proposed are discussed, rigorous accurate treatment incorporating charge-carrier-induced lattice strain correct statistics is presented. Considering all contributing effects, we find that compensation energy primary contribution to enhancement essentially material systems interest. An exception...