The electronic levels of vanadium in semi-insulating 4H- and 6H-SiC have been reinvestigated using temperature dependent Hall effect and resistivity measurements at temperatures up to 1000 K in conjunction with electron paramagnetic resonance (EPR) and optical absorption measurements... (Read more)

Silicon carbide nanotubes have a great potential for biological applications. It is of interest to explore the electronic properties of these nanotubes, and how those are modified in the presence of impurities. Hydrogen is a common impurity that can appear during the growth of silicon carbide... (Read more)

We calculate the fine structure splitting of the near band edge donor-bound excitons in major cubic semiconductors using an approach inspired by an earlier one that consists in replacing the Morse potential by a Kratzer one, in order to account for the repulsion between the donor and the hole. A... (Read more)

Phosphorus is the n-type dopant of choice for diamond, but results in a deep donor level and alternatives are being sought. One possibility is the incorporation of interstitial alkali metal impurities such as Li and Na. We present the results of density-functional calculations used to predict... (Read more)

We report the diffusion of boron, arsenic, and phosphorus in silicon isotope multilayer structures at temperatures between 850 °C and 1100 °C. The diffusion of all dopants and self-atoms at a given temperature is modeled with the same setting of all native-point-defect-related parameters.... (Read more)

The formation of hydrogenlike muonium (Mu) has been studied as a function of implantation energy in intrinsic Si, thin films of condensed van der Waals gases (N₂, Ne, Ar, Xe), fused and crystalline quartz, and sapphire. By varying the initial energy of positive muons... (Read more)

The asymmetry doping problem has severely hindered the potential applications of many wideband gap (WBG) materials. Here, we propose a possible approach to overcome this long-standing doping asymmetry problem for WBG semiconductors. Our approach is based on the reduction of the ionization energies... (Read more)

Existing defect models for In₂O₃ and ZnO are inconclusive about the origin of conductivity, nonstoichiometry, and coloration. We apply systematic corrections to first-principles calculated formation energies ΔH, and validate our theoretical defect model against... (Read more)

The authors present the results of electrically detected magnetic resonance (EDMR) experiments on ion-implanted Si:P nanostructures at 5 K, consisting of high-dose implanted metallic leads with a square gap, in which phosphorus is implanted at a nonmetallic dose corresponding to 10¹⁷ ... (Read more)

Recombination centers in thin asymmetrical p-n junctions were analyzed in the context of capacitance transient experiments. The combined effect of the thin low-doped region of the junction and the nonzero value of the occupation factor of the recombination center in the depletion layer... (Read more)

We report low-frequency charge noise measurement on silicon substrates with different phosphorus doping densities. The measurements are performed with aluminum single electron transistors (SETs) at millikelvin temperatures where the substrates are in the insulating regime. By measuring the SET... (Read more)

Phosphorus-doped ZnO films were grown by molecular-beam epitaxy with a GaP effusion cell as dopant source. Three growth regions were identified to obtain ZnO films with different conduction types. In the oxygen-extremely-rich region, phosphorus-doped ZnO films show n-type conduction with... (Read more)

This paper addresses some of the fundamental issues and critical advantages in reducing the grain size/feature size to the nanoscale regime. We find that as the grain size or feature size is reduced, there is a critical size below which the defect content can be reduced virtually to zero. This... (Read more)

Sulfur ions are implanted into 6H-, 4H-, and 3C-SiC. Admittance and double correlated deep level transient spectroscopy investigations reveal that S atoms form double donors in SiC, which reside on lattice sites. The number of double donors observed corresponds to the number of... (Read more)

Computational techniques are key predictive tools in the drive to engineer semiconductive materials. Diamond, intrinsically a wide band-gap insulator, can be made to semiconduct n-type by doping with phosphorus. However, the relatively deep level at E_c−0.6 eV... (Read more)

Hexagonal SiC is either co-implanted with silicon (Si⁺), carbon (C⁺), or neon (Ne⁺) ions along with nitrogen (N⁺) ions or irradiated with electrons (e⁻) of 200 keV energy. During the subsequent annealing step at temperatures above 1450 ... (Read more)

The electrical resistivity of 4H-SiC doped with nitrogen is analyzed in the temperature range 10–700 K for nitrogen concentrations between 3.5×10¹⁵ and 5×10¹⁹ cm⁻³. For the highest doped samples, a good agreement is found between the... (Read more)

We investigate transport properties of ultrananocrystalline diamond films for a broad range of temperatures. Addition of nitrogen during plasma-assisted growth increases the conductivity of ultrananocrystalline diamond films by several orders of magnitude. We show that films produced at low... (Read more)

We investigate transport in phosphorus-doped buried-channel metal-oxide-semiconductor field-effect transistors at temperatures between 10 and 295 K. We focus on transistors with phosphorus donor concentrations higher than those previously studied, where we expect conduction to rely on donor... (Read more)

Resonant interaction between longitudinal-optic (LO) phonons and electrons bound on shallow donors in GaN is studied using magnetoluminescence of neutral-donor bound excitons (D⁰X). The experiments were performed on high-quality freestanding GaN material and heteroepitaxial... (Read more)

Magnetic resonance of electrons in lightly doped GaAs layers has been detected at 5.8 T by magneto-optical Kerr rotation. A study over a wide range of microwave powers shows (1) resonance without dynamic nuclear polarization (DNP), (2) resonance enhanced by DNP, and (3) DNP pinning of the resonance... (Read more)

Two-dimensional electron systems fabricated from a single layer of P-donors have been lithographically confined to nanometer scale in lateral directions. The electronic transport of such quasi-one-dimensional systems with and without a perpendicular magnetic field was characterized at cryogenic... (Read more)

We compute within the effective-mass theory and without adjustable parameters the Stark effect for shallow P donors in Si with anisotropic band structure. Valley-orbit coupling is taken into account in a nonperturbative way and scattering effects of the impurity core are included to properly... (Read more)

We present a comprehensive spin-density functional modeling study of the structural and electronic properties of donor-vacancy complexes (PV, AsV, SbV, and BiV) in Ge crystals. Special attention is paid to spurious results which are related to the choice of the boundary... (Read more)

Continuous-wave (cw) electron paramagnetic resonance (EPR) at both X-band and W-band frequencies, pulsed-EPR, and pulsed electron nuclear double resonance (ENDOR) were used to study phosphorus shallow donors in 3C-, 4H-, and 6H-SiC doped with phosphorus (P) during... (Read more)

We resolve the remarkably sharp bound exciton transitions of highly enriched ²⁸Si using a single-frequency laser and photoluminescence excitation spectroscopy, as well as photocurrent spectroscopy. Well-resolved doublets in the spectrum of the ³¹P donor reflect the hyperfine... (Read more)

We report Stark shift measurements for ¹²¹Sb donor electron spins in silicon using pulsed electron spin resonance. Interdigitated metal gates on a Sb-implanted ²⁸Si epilayer are used to apply the electric fields. Two quadratic Stark effects are resolved: a decrease of the... (Read more)

The hyperfine interaction of phosphorus donors in fully strained Si thin films grown on virtual Si_1-xGe_x substrates with x0.3 is determined via electrically detected magnetic resonance. For highly strained epilayers, hyperfine interactions as low as 0.8 mT... (Read more)

It has been an accepted fact for more than 40 years that the E center in Si (the group-V impurity—vacancy pair)—one of the most studied defects in semiconductors—has only one energy level in the band gap: namely, the acceptor level at about 0.45 eV below the conduction... (Read more)

Phosphorus shallow donors having the symmetry lower than Td are studied by pulsed EPR. In diamond:P and 3C–SiC:P, the symmetry is lowered to D2d and the density of the donor wave function on the phosphorus atom exhibits a predominant p-character. In 4H–SiC:P with the site symmetry of... (Read more)

Zinc oxide crystals grown by the seeded chemical vapor transport method have been annealed in zinc vapor at 1100 °C for 30 min. These thermochemical reduction treatments produce a deep red coloration in the crystals and increase their n-type electrical conductivity. Electron paramagnetic... (Read more)

Freeze-drying, as a cryochemical powder processing method is applied in the synthesis of ZnO submicrometer to nanosized powders. The process involves rapid freezing of the sprayed precursor solution, drying under vacuum by sublimation of the solvent and salt decomposition to oxide by thermal... (Read more)

Shallow N donors in n-type 4H-SiC were studied by electron paramagnetic resonance (EPR) and electron nuclear double resonance (ENDOR). For the N donor at the cubic site (N_k) in 4H-SiC, the hyperfine (hf) constants of the interaction with the nearest-neighbor... (Read more)

Combining efficient density-functional based tight-binding molecular dynamics with ab initio calculations, we show that despite higher formation energies the incorporation of phosphorus at the carbon sublattice is favored by kinetic effects during the annealing processes. Based on the... (Read more)

Hole burning in and displacements of the magnetic-resonance absorption line of the electron spin of the shallow hydrogen-related donor in ZnO are observed upon resonant irradiation with microwaves at 275 GHz and at 4.5 K in a magnetic field of 10 T. These effects arise from an almost complete... (Read more)

ZnO nanocrystals with diameters ranging from 4 to 50 nm were prepared via a wet chemical method and post-growth annealing treatments. The electron paramagnetic resonance (EPR) spectra of the nanocrystals show the resonance of electron centers with g-value close to that of the shallow donors in bulk... (Read more)

Phosphorus ion implantations of 6H-SiC in the mean phosphorus concentration of the implanted layer of 1 × 1018 cm−3 were performed both at multi-fold energy between 9 and 21 MeV and at 340 keV. In the high-energy implantations at room temperature, 400, 800 and 1200 °C and in the 340... (Read more)

The selection rules for transitions between the electronic levels of shallow donors in 4H-SiC in the dipole approximation are derived. The ionization energy of the shallow nitrogen donor (at hexagonal site) is determined to be 61.4±0.5 meV by analyzing the photothermal ionization and... (Read more)

We report the identification of the nitrogen-vacancy-hydrogen complex in a freestanding nitrogen-doped isotopically engineered single crystal diamond synthesized by chemical vapor deposition. The hydrogen atom is located in the vacancy of a nearest-neighbor nitrogen-vacancy defect and appears to be... (Read more)

Spin-lattice relaxation time (T₁) and phase memory time (T_M) of shallow donors in 3C-, 4H- and 6H-SiC have been measured in time domain by using pulsed EPR technique. The temperature dependence of T₁ suggests that the Orbach process should be frozen at relatively high temperatures. Shallow donors in SiC are promising in attaining a sufficiently long phase memory time at temperatures much higher than Si:P. (Read more)

A defect associated with Li in ZnO is reported. This is an optical system which absorbs strongly in the red part of the spectrum: a doublet, the zero phonon lines are at 1.884 and 1.879 eV, respectively. The chemical nature of the centre is identified through isotope substitution. This is the first... (Read more)

Recent results from studies of shallow donors, pseudodonors, and deep level defects in SiC are presented. The selection rules for transitions between the electronic levels of shallow donors in 4H–SiC in the dipole approximation are derived and the ionization energy for the N donor at... (Read more)

Nitrogen acceptors are formed when undoped single crystals of zinc oxide (ZnO) grown by the chemical-vapor transport method are annealed in air or nitrogen atmosphere at temperatures between 600 and 900 °C. After an anneal, an induced near-edge absorption band causes the crystals to appear... (Read more)

Previous calculations on n-type doping of diamond by P and S predicted that S has a shallower level and a higher solubility than P. Our first-principles calculations show that the opposite is true: Phosphorus impurity in diamond gives rise to a shallower donor level, and has a higher bulk solid... (Read more)

Electron paramagnetic resonance (EPR) and optically detected magnetic resonance (ODMR) experiments have been performed on a set of GaN epitaxial layers doped with Mg from 2.5?10¹⁸ to 5.0?10¹⁹ cm^-3. The samples were also characterized by secondary-ion-mass... (Read more)

Electron paramagnetic resonance and Hall measurements show consistently the presence of two donors ( D1 and D2) in state-of-the-art, nominally undoped ZnO single crystals. Using electron nuclear double resonance it is found that D1 shows hyperfine interaction with more than 50 shells of surrounding... (Read more)

Photosensitive electron paramagnetic resonance (EPR) investigations of unintentionally doped, semi-insulating (s.i.) 4H?SiC have been made at 37 GHz and 77 K including photoexcitation and photoquenching experiments. In the dark the EPR spectrum consists of a low intensity line due to boron on the... (Read more)

In this paper, we present high-frequency (95 GHz) pulsed electron paramagnetic resonance (EPR) and electron nuclear double resonance (ENDOR) measurements on the nitrogen (N) donor in 4H-SiC (k site) and 6H-SiC (h, k₁, and k₂ sites according to the accepted classification). From... (Read more)

Electron spin resonance experiments were performed on Si-doped wurtzite and zinc-blende GaN and Si-doped wurtzite Al_xGa_1-xN alloys with x=0.15, 0.32, 0.52, 0.75, and 1. For zinc-blende GaN, an isotropic g factor of 1.9475 is found. The g tensors of the silicon effective mass... (Read more)

We have used EPR and ODMR to study state-of-the-art bulk ZnO single crystals. Most of the samples are n-type; however, under certain conditions (e-irradiated or annealed), we observe a center due to residual nitrogen (g||=1.9953, g=1.9633 and Aiso=1.225 mT, Aaniso=0.864 mT). The N center is a... (Read more)

Magnetic resonance experiments, including optically detected magnetic resonance (ODMR) and electron paramagnetic resonance (EPR), have been performed on Si-doped homoepitaxial GaN layers grown by MOCVD and on high quality, free-standing (200 μm-thick) GaN grown by HVPE. This allowed us to... (Read more)

Comparisons are made between the carrier concentrations, ionization energies, and electron mobilities in 4H–SiC samples implanted with similar doses of nitrogen or phosphorus and annealed at 1300 or 1700 °C for 10 min in argon. The objective of the research is to determine which element may... (Read more)

Photothermal ionization spectroscopy (PTIS) measurements were carried out on a free-standing, high purity and high quality 4H–SiC epitaxial layer at various temperatures. The two step photothermal ionization process is clearly reflected in the temperature dependence of the photoconductivity.... (Read more)

The passivation by hydrogen of selenium double donors in silicon has been investigated by magnetic resonance. Hydrogen was introduced by heat treatment at high temperatures in an atmosphere of water vapor. Two spectra were observed, labeled Si-NL60 and Si-NL61 for further reference, both showing... (Read more)

Two phosphorus centers in SiC, an isolated P atom substituting for Si (P_Si) and a Si-site P-atom adjacent to a carbon vacancy (P_Si+V_C) are investigated by first principle calculations. It is shown that P_Si+V_C produces a singly occupied donor... (Read more)

N-type silicon doped with gold and lithium was investigated by Electron Paramagnetic Resonance (EPR) and Deep Level Transient Spectroscopy (DLTS), using two sets of samples with different defect concentrations of both gold and lithium. Photoluminescence (PL) on both sets of samples allowed to... (Read more)

Nitrogen donors in 6H-, 4H- and 3C-SiC were investigated using conventional electron paramagnetic resonance (EPR) and electron nuclear double resonance (ENDOR) and the experimental results are discussed. An attempt is presented to interpret the experimentally found large differences in hyperfine... (Read more)

Investigations of nitrogen donors in 6H-, 4H- and 3C-SiC using conventional electron paramagnetic resonance (EPR), electron nuclear double resonance (ENDOR) and optical detection of EPR and ENDOR as well as optical absorption and emission spectroscopy are reviewed and critically discussed. An... (Read more)

The temperature dependence of the paramagnetic susceptibility of donor centers in zinc-blende GaN thin films observed by monitoring the integral intensity of the electron paramagnetic resonance (EPR) absorption has been analyzed using the donor-molecule model. The theoretical predictions are... (Read more)

Single crystal GaN thin films resulting from various deposition techniques are usually dominated by residual donors. To date, the true nature of this donor conduction is not known. Nitrogen vacancies, residual oxygen, and growth defects are cited as potential causes for the residual n-type... (Read more)

Electron-spin-resonance (ESR) measurements have been performed on a series of wurtzite GaN films grown on sapphire substrates by low-pressure metal-organic chemical-vapor deposition. The sample set included films grown with both AlN and GaN buffer layers. The ESR signal results from residual donors... (Read more)

We report electron-spin-resonance measurements on zinc-blende GaN. The observed resonance has an isotropic g value of 1.9533±0.0008 independent of temperature, a Lorentzian line shape, and a linewidth (18 G at 10 K) which depends on temperature. The spin-lattice relaxation time at 10 K was... (Read more)

It is demonstrated that hydrogen can migrate in silicon as a negatively charged species (H^-). The evidence is the combined observation of a strong electric-field dependence in the rate of removal of PH complexes during bias-temperature stress of hydrogenated Schottky-barrier diodes and... (Read more)

Shallow donors in ZnO were studied by electron spin resonance (ESR) and optically detected magnetic resonance (ODMR). Indium and gallium donors were identified by their hyperfine structure. They have g|| = 1.957 and g = 1.956 and the hyperfine constants are A(69Ga)=4.2 and A(115In)=36.6 G. The ESR... (Read more)

Application of optically detected ESR to the yellow photoluminescence of Li doped ZnO gives ESR spectra for shallow donor - lithium acceptor pairs, showing that at least a fraction of the yellow emission is donor-acceptor (D-A) luminescence. The distribution of separations rDA gives a spectrum of... (Read more)

The hyperfine interactions of Si²⁹ lattice nuclei with ground-state donor electrons in arsenic-, phosphorus-, and antimony-doped silicon have been measured by electron-nuclear double resonance (ENDOR). Hyperfine constants are reported for each donor for about 20 shells containing a total... (Read more)

Effects of exchange and motion on electron spin resonance spectrum of phosphorus doped Si with concentration of 3×10¹⁶cm^-3～3×10¹⁹cm^-3 were investigated at liquid helium temperatures and at about 9300 Mc/sec. At lower concentrations, the intensity of... (Read more)

The solubilities of substitutional and interstitial copper (Cu^s and Cuⁱ) have been measured in intrinsic and extrinsic n- and p-type Ge, Si, and GaAs, using Cu⁶⁴. These measurements show that Cu^s is a triple acceptor in... (Read more)

The excited states of the antimony, phosphorus, and arsenic impurities in silicon have been investigated by subjecting samples to a uniaxial stress and observing the change in the electron spin resonance spectrum. The experiments were performed at 1.25?K and ?9000 Mc/sec on silicon samples subjected... (Read more)

The different relaxation processes that connect the four energy levels in phosphorus doped silicon have been investigated experimentally. The relaxation time T_s (?m_s=?1, ?m_I=0) was found to be independent of phosphorus concentration below ?10¹⁶... (Read more)

The spin and magnetic moment of 14-day P³² with dtermined by the electron unclear double resonance (ENDOR) technique.The P³² obtained from Oak Ridge was diffused into high-resistivity silicon plates having a total volume of 0.25 cm³. (Read more)

I. Introduction (p.258): II. Emprical Properties (p.261): 1. Energy Levels (p.261), a. Ionization Energies, b. Spectra of Excited States, 2. Spin Resonance (p.266), a. Electron Spin Resonance, b. Double Resonance, 3. Static Magnetic Susceptibility (p.271), III. Structure of Donor States (p.271): 4. Conduction Bands of Silicon and Germanium (p.271), a. Silicon, b. Germanium, 5. Effective Mass Theory of Donor States (p.274), a. Single Band Minimum at k=0, b. Several Conduction Band Minima, c. Matrix Elements for Radiative Transitions, 6. Numerical Results and Comparison with Experiments (p.285), a. Energy Levels, b. Wave Functions, 7. Corrections to the Effective Mass Formalism (p.289), a. General Considerations, b. Corrected Wave Functions, c. Comparison with Experiment, IV. Structure of Acceptor States (p.297): 8. Valence Bands of Silicon and Germanium (p.297), a. Silicon, b. Germanium, 9. Effective Mass Equations for Acceptor States (p.300), 10. Approximate Solutions and Comparison with Experiment (p.301) a. Germanium b. Silicon V.Effects of Strains and of Static Electric and Magnetic Fields (p.306): 11. Strains (p.306) a. Donor States, b. Acceptor States, 12. Stark Effect (p.311)

The double-frequency resonance method reported recently in connection with a unclear polarization schemehas been extended to observe unclear transitions and thereby determine hyperfine interactions and unclear g values. (Read more)

In the preceding Letter a scheme for polarizing unclei was described.This letter deals with the experimental verificationof the scheme. (Read more)

By using the recently measured effective masses for n-type Si, m₁=0.98 m and m₂=0.19 m, approximate solutions of the resulting effective mass Schroedinger equation are obtained. The accuracy of the solutions was tested in the limiting cases where... (Read more)