In this paper we review paramagnetic point defects in amorphous silicon nitride thin films. We will discuss two intrinsic defects: a trivalent center, named the K‐center, and recently observed nitrogen dangling‐bond center. examine structural identification, electronic properties of as well consider why is generally very effective charge trapping dielectric. addition, compares contrasts special features structure role both dioxide films; may provide insight for further studies on physics...

In the present paper, Cu(I)-catalyzed intramolecular aminotrifluoromethylation of O-homoallyl benzimidates with Togni reagent I was reported. O-Homoallyl equipped terminal alkenes produced chiral 1,3-oxazines high enantioselectivity in presence a BOX ligand, and racemic tetrahydro-1,3-oxazepines were obtained yields from internal alkene derivatives monoprotected amino acid additive under similar conditions.

We report the observation of both silicon and nitrogen paramagnetic defect centers using X-band Q-band electron spin resonance microwave excitation frequencies. By two different frequencies along with a computer analysis lineshapes, we have been able to confirm extend earlier observations regarding chemical identity these defects. Specifically, provide additional evidence that dangling bond, i.e., K center, is an unpaired on atom bonded three atoms in stoichiometric nitride. further...

Optical detection of magnetic resonance is reported for isolated interstitial ${\mathrm{Zr}}_{1}^{+}$ in ZnSe produced by 2.5-MeV electron irradiation at 4.2 K. It detected as a reduction the distant-donor--to--Frenkel-pair recombination luminescence 625 nm. Resolved hyperfine interaction with central zinc ion and two shells Se neighbors reveals highly localized ``deep'' state paramagnetic electron. stable only to \ensuremath{\sim}220

Lithium batteries have revolutionized energy storage with their high density and long lifespan, but challenges such as limitations, safety, cost still need to be addressed. Crystalline materials, including Ni-rich cathodes lithium anodes, play pivotal roles in the performance of high-energy-density batteries. Understanding micro-scale behavior degradation mechanisms these materials is crucial for improving macro-scale battery performance. Simulation methods, particularly machine learning...

Zinc vacancies (${\mathit{V}}_{\mathrm{Zn}}$), zinc interstitials (${\mathrm{Zn}}_{\mathit{i}}$), and \ensuremath{\sim}25 distinct ${\mathit{V}}_{\mathrm{Zn}}$--${\mathrm{Zn}}_{\mathit{i}}$ Frenkel pairs of different lattice separations are observed in ZnSe by the optical detection magnetic resonance photoluminescence after 2.5 MeV electron irradiation situ at 4.2 K. The stability, energy, anisotropy production vs beam direction, plus exchange dipole-dipole interactions excited emitting...

Optical detection of magnetic resonance is reported for three distinct zinc-vacancy-zinc-interstitial Frenkel pairs in ZnSe produced by 2.5-MeV electron irradiation at 4.2 K. One detected as distant-donor-to-Frenkel-pair recombination luminescence \ensuremath{\sim}600 nm. The other two are localized-triplet \ensuremath{\sim}800 emitting excitonic state analyzed a hole on the zinc vacancy with an exchange-coupled nearby interstitial zinc. From this, EPR properties isolated donor deduced.

The Pb-like dangling-orbit centers in luminescent porous silicon (LPSi) have been enhanced to very high concentration (1015 cm−2) by gentle oxidation. High signal-to-noise ratio and sharp lines enable the g-value maps, 29Si hyperfine superhyperfine structures be clearly resolved ordinary EPR. Only one center is observed, it proven of Pb0 variety (⋅Si≡Si3). relative EPR signal strengths from different g limbs indicate that LPSi crystallite morphology not dominated needles or platelets.

The Fermi level position in low temperature (LT) GaAs has been studied by photoreflectance (PR). By etching the LT-GaAs to a different thickness, we find as-grown as well annealed is firmly pinned. pinning position, however, occurs at energies: 0.47 eV below conduction band edge for samples and 0.65 samples. believed be result of high degree charge compensation deep levels, while due depletion carriers Schottky barrier metallic As precipitates. From measured ionization ratio antisites, (0/+)...

A hyperfine structure has been observed by electrically detected magnetic resonance from a Si p–n diode. From the splitting, and natural abundance of interacting I=1/2 nuclear species, recombination center is found to be consistent with platinum complex.

We have examined the behavior of Si dangling-bond center in regard to charge trapping N-rich amorphous hydrogenated silicon nitride thin films. The effects multiple electron and hole injections were monitored by paramagnetic resonance. These results continue support a model which dangling bond is negative U defect nitrides, that change state pre-existing diamagnetic positively negatively charged sites responsible for memory properties

Arsenic antisites in GaAs layers grown by molecular-beam epitaxy at low substrate temperatures (∼200 °C) were observed using electron paramagnetic resonance (EPR), magnetic circular dichroism absorption (MCDA), and MCDA-detected EPR. This observation confirms that there is a MCDA band directly associated with arsenic the layers.

We describe optical detection of magnetic resonance for 17 well-resolved discrete zinc interstitial donor-zinc vacancy acceptor pairs varying separation in ZnSe. For most the pairs, microwave transitions are detected between exchange split triplet and singlet manifolds giving a direct high-precision measurement separated electron hole interaction excited emitting state each pair. From these studies E(+/2+) second donor isolated atom is estimated to be \ensuremath{\sim}${E}_{c}$-0.8 eV.

We report the first observation of positively charged Pb+3 defect centers in lead zirconate titanate (PZT) ceramics using electron paramagnetic resonance. The traps were optically generated ultraviolet light energies roughly corresponding to band gap PZT (3.4 eV). interpretation 207Pb+3 hyperfine parameters indicates that defect’s unpaired is approximately 48% localized on Pb nucleus. These observations may be considerable importance since they prove carriers created by optical excitation...

A strong optically detected magnetic-resonance (ODMR) spectrum is obtained by the monitoring of a broad luminescence band peaking at 0.83 eV in as-grown Zn-doped GaAs. Our analysis firmly establishes localized spin-triplet character and trigonal 〈111〉-oriented symmetry axis corresponding defect. This type ODMR has only been tentatively identified GaAs previously.

We have reproduced and extended some recently reported electron spin resonance (ESR) measurements related to the nature of dominant charge traps in silicon nitride. detected defect centers at low temperatures using ESR, both as-deposited ultraviolet-irradiated nitride powders films prepared by low-pressure chemical vapor deposition (LPCVD). Only two dangling bond defects were observed nitride, one g=2.003 (⋅Si≡N3), other g=2.005 (⋅Si≡Si3). The signal intensity is far LPCVD subjected UV...

An optically detected electron-nuclear double resonance (ODENDOR) study of the phosphorus antisite-related defect ${\mathrm{P}}_{\mathrm{Ga}\mathrm{\ensuremath{-}}}$${\mathit{Y}}_{\mathrm{P}}$ in GaP is presented. Observed an excited S=1 state via photoluminescence at \ensuremath{\sim}1.1 eV, it established that observed ODENDOR transitions arise from ${\mathit{M}}_{\mathit{s}}$=0 state. The serves as a model to demonstrate unusual features spectroscopy this state, for which there are no...

Arsenic antisites produced in GaAs by room-temperature electron irradiation (RTEI) are examined paramagnetic resonance (EPR). For the first time, this RTEI antisite, which has been believed to be isolated is found metastable. The most efficient photon energy for photoquenching approximately 1.15 eV, very close that observed well-known EL2 center undoped semi-insulating GaAs. However, thermal recovery temperature about 200–250 K, much higher than center.