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Electrical properties of a ZnO microwire grown by carbo-thermal evaporation, a ZnO thin film grown by pulsed-laser deposition and a hydrothermally grown ZnO bulk crystal are compared. Deep defects were investigated by means of deep-level transient spectroscopy. The defect level E3 was observed in all samples investigated. Additionally, a defect labelled T2 that preferentially forms under Zn-rich condition was detected in the microwire, the thin film and the bulk sample. Our results indicate that V Zn is likely involved in this defect.

Deep-level transient spectroscopy measurements have been performed on the quaternary semiconductor InGaAsN. A series of as-grown and annealed metalorganic chemical-vapor-deposited and molecular-beam-epitaxy samples with varying composition were studied. We observed a deep hole trap with activation energy ranging between 0.5 and 0.8 eV in all samples. The data clearly obey the Meyer–Neldel rule (MNR) with an isokinetic temperature of 350 K. We show that great care must be used in extracting capture cross sections (σ) from materials that obey the MNR. In fact, we argue that it is probably not possible to determine σ from the detrapping rate alone. One must measure both trapping and detrapping rates.

Deep-level transient spectroscopy measurements in InAs quantum dots (QDs) grown in both n-GaAs and p-GaAs show that tunneling is an important mechanism of carrier escape from the dots. The doping level in the barrier strongly affects the tunneling emission rates, enabling or preventing the detection of a transient capacitance signal from a given QD level. The relative intensity of this signal acquired with different rate windows allows the estimation of tunneling emission energies.

The behavior of detector-grade Cd0.9Zn0.1Te in a radiation-hostile environment has been investigated by studying the effects on the material defective states induced by γ irradiation. The detector performance is strongly affected by the presence of charge-trapping centers which may also intervene in the material compensation properties. We have investigated by photoinduced current transient spectroscopy analyses the evolution with increasing irradiation dose of the deep levels both present in the as-grown material and induced by the ionizing radiation. A significant correlation between the material resistivity and some deep levels behavior has been observed. We have compared this trend to the results obtained from γ-irradiated CdTe:Cl to better understand the role deep traps play in the compensation process of II–VI materials.

We show that the usual Arrhenius analysis of the main electron-irradiation-induced defect trap in n-type GaN, observed by deep-level transient spectroscopy (DLTS), is not sufficiently accurate. Instead, an exact fitting of the DLTS spectrum for this trap reveals two components, each of which has a thermal energy near 60 meV, not the apparent 140–200 meV, as given in other DLTS studies. This result resolves the discrepancy between Hall-effect and DLTS determinations of the thermal energy of this defect center.

Capacitance-frequency measurement is used to study In0.12Ga0.88As/GaAs p-i-n superlattice, with superlattice layer grown at 300 °C by molecular-beam epitaxy. Three traps are observed, and their parameters are consistent with those obtained from deep-level transient spectroscopy. Among these three traps, the trap (Ea=0.45±0.02 eV, σ=6±4×10−17 cm2) shows an abnormal increase of capacitance with increasing frequency, similar to that observed from the 0.66 eV trap in low-temperature grown GaAs p-i-n structure, suggesting that it is created by the low-temperature growth and is a generation-recombination center. This result also shows that the capacitance-frequency measurement is effective in studying the generation-recombination centers.

The correspondence between the E2 level (∼Ec−0.55 eV) in n-type GaN undergoing thermoionization and photoionization was established. The optical cross section in the vicinity of the threshold for photoionization of this level was measured by means of capacitance transient spectroscopy. Analysis using the formulation of Chantre yielded the optical activation energy, Eo=0.85 eV, and the Franck–Condon parameter, dFC=0.30 eV at 90 K.The correspondence between the E2 level (∼Ec−0.55 eV) in n-type GaN undergoing thermoionization and photoionization was established. The optical cross section in the vicinity of the threshold for photoionization of this level was measured by means of capacitance transient spectroscopy. Analysis using the formulation of Chantre yielded the optical activation energy, Eo=0.85 eV, and the Franck–Condon parameter, dFC=0.30 eV at 90 K.

We report that the Te donor forms a deep level and acts as a DX center in In1−xGaxAsyP1−y/GaAs0.61P0.39. The characteristics of Te‐related deep level is investigated by deep‐level transient spectroscopy and thermally stimulated capacitance measurements. The deep level has a thermal activation energy of 0.14±0.01 eV regardless of the alloy composition of In1−xGaxAsyP1−y. Persistent photoconductivity is observed at low temperature in all Te‐doped In1−xGaxAsyP1−y/GaAs0.61P0.39 samples. The compositional dependence of deep trap density is explained by the energy difference between the conduction band minimum and the DX level.

We report a two‐step growth process, using an atomic layer epitaxially grown GaAs predeposition layer for the growth of GaAs/Si layers by metalorganic vapor phase epitaxy technique. Photoluminescence and deep‐level transient spectroscopy techniques are used to show that the quality of the grown material is comparable to that grown by a much complicated procedure involving strained layer superlattice buffers introduced between the active GaAs layer and the Si substrate.

Through temperature‐dependent conductivity measurements, we show evidence of a deep trap level in low‐temperature (LT) Al0.3Ga0.7As layers with an activation energy of ∼0.96 eV. This energy is near that of EL2‐like defects found previously in ‘‘normal’’ epitaxial Al0.3Ga0.7As. It is also considerably larger than the 0.70 eV value typically associated with defects in LT GaAs, which may explain the observed large resistivity (≳1011 Ω cm) in LT Al0.3Ga0.7As. Current transient spectroscopy (CTS) of these samples yields a deep level activation energy of 1.01 eV, in close agreement with the value obtained from conductivity measurements.

Two different kinds of n‐type GaN films were prepared by organometallic vapor phase epitaxy, one by using trimethylgallium (TMGa) and another by using triethylgallium (TEGa) as the alkyl source. Schottky diodes with well‐behaved current–voltage and capacitance–voltage characteristics were fabricated. Deep‐level transient spectroscopy studies were performed on these samples. Three distinct deep levels, labeled E1, E2, and E3, were measured in the film grown with TMGa, with an activation energy of 0.14, 0.49, and 1.63±0.3 eV, respectively. Only one level, E3, was observed in the film prepared with TEGa.

Two deep electron traps induced by lattice mismatch in relaxed GaAs1−xSbx layers (x=0% to 3%) grown by liquid phase epitaxy (LPE) on GaAs substrates have been revealed by means of deep‐level transient spectroscopy. One of the traps, that shows nonstandard, logarithmic capture kinetics and whose energy level is tied to the valence‐band edge, has been related to electron states associated with α dislocations. The other trap has been attributed to the EL2 defect and possible reasons of its unexpected formation in the LPE‐grown layers are briefly discussed.

The electrical properties of molecular beam epitaxy (MBE) grown low‐temperature GaAs (LT‐GaAs) by current transient spectroscopy (CTS) has been investigated. At least three deep traps have been observed in LT‐GaAs grown at 250 °C and annealed at 600 °C. The deepest level is dominant and has an activation energy of 0.82 eV, which is the same as that of the midgap donor, EL2. This is consistent with the activation energy of resistivity of this sample (0.77 eV), which is close to that for bulk nondoped semi‐insulating wafers. These results indicate that the Fermi level of annealed LT‐GaAs grown at 250 °C is pinned by the deep level at the midgap that is generally ascribed to AsGa antisite defects.

The effect of iron charge state on its diffusion in p‐type Si near room temperature has been investigated by C–V and depth dependent deep‐level transient spectroscopy measurements. The migration enthalpies of both positively charged and neutral iron were found to be 0.92 and 0.56 eV, respectively. Disagreement between the theoretical predictions and experimentally observed trend in iron diffusion is briefly discussed in terms of diffusion path, elastic strain, and Coulombic interaction versus impurity charge state.

A GaP n+p-diode containing In0.5Ga0.5As quantum dots (QDs) and an AlP barrier is characterized electrically, together with two reference samples: a simple n+p-diode and an n+p-diode with AlP barrier. Localization energy, capture cross-section, and storage time for holes in the QDs are determined using deep-level transient spectroscopy. The localization energy is 1.14(±0.04) eV, yielding a storage time at room temperature of 230(±60) s, which marks an improvement of 2 orders of magnitude compared to the former record value in QDs. Alternative material systems are proposed for still higher localization energies and longer storage times.

Photoinduced current transient spectroscopy has been used to show the effect of thermal annealing on deep level defects in semi‐insulating Fe doped InP wafers. The annealing experiments have been accomplished in an infrared image furnace during 15 min at temperatures ranging from 663 to 820 °C. We show that this treatment leads to the formation of four deep traps named T1–T4 having the following activation energies: 0.14, 0.21, 0.41, and 0.53 eV, respectively. We show that the thermal anneal at high temperature leads to deterioration of the electrical properties of the material.

The localization energies, capture cross sections, and storage times of holes in GaSb quantum dots (QDs) are measured for three GaSb/GaAs QD ensembles with different QD sizes. The structural properties, such as height and diameter, are determined by atomic force microscopy, while the electronic properties are measured using deep-level transient spectroscopy. The various QDs exhibit varying hole localization energies corresponding to their size. The maximum localization energy of 800 (±50) meV is achieved by using additional Al0.3Ga0.7As barriers. Based on an extrapolation, alternative material systems are proposed to further increase the localization energy and carrier storage time of QDs.

We investigated the deep-level traps formed in Cr-SrTiO3/Si3N4/SiO2 structures deposited on n-type Si by deep-level transient spectroscopy (DLTS). Three electron traps, with averaged activation energies of 0.24, 0.28, and 0.53 eV, were observed below the conduction band minimum of Si. Different behaviors in the dependence of DLTS on both filling bias and pulse confirm that the traps originate as the Si3N4 bulk trap, the Si3N4/SiO2 interfacial trap, and the Si/SiO2 interfacial trap. We also demonstrate that a specific point defect is the source of memory behavior in Cr-SrTiO3-based fusion-type charge trap flash (CTF) memory devices.

Admittance spectroscopy and deep-level transient spectroscopy measurements have been performed on n+-on-p Hg1−xCdxTe (x=0.595) planar photodiodes grown by improved zone melt method. After 1.0 Mrads gamma irradiation, a new trap center is observed at 0.19 eV above the valence band, while the well-known 0.15 eV trap level disappears. The trap densities for these two levels are almost the same. We attribute this phenomenon to the gamma irradiation, which produces a compound defect correlated with Hg vacancy.

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 caused electrons and holes to be simultaneously released from different parts of this layer during an emission transient. The need to introduce modifications in the analytical expressions that determine the parameters of these centers by capacitance transient spectroscopy is demonstrated. A correction formula to determine concentrations of electron or hole traps or recombination centers is proposed.

We use deep-level transient spectroscopy (DLTS) to investigate the electronic properties of ZnO∕CdS∕CuxIn1−yGaySe2∕Mo∕soda-lime glass thin-film solar cells. We deposited films with different x and y values using elemental evaporation. Devices made from these films exhibit more than 40 hole and electron traps, with activation energies ranging from 0.07to1.17eV. Standard DLTS analysis (which assumes that entropy changes can be neglected) gives apparent capture cross sections that vary by 18 orders of magnitude over this energy range. All our data show that the charge-carrier emission rate obeys the Meyer-Neldel rule (MNR) with an isokinetic temperature of 340±30K. By including the MNR relation in detailed balance, we show that there is a single cross section for all the traps.

We have investigated by capacitance transient spectroscopy concentration profiles of gold produced by electrotransport and concentration variations by pairing of gold with iron in p‐type silicon. We have found that the line amplitude of the gold donor and that of the gold acceptor have a constant radio independent of gold concentration, diffusion temperature, and of gold‐iron‐pair concentration. From this result we conclude that the two levels are associated with one gold species in silicon.

The introduction and annealing of defect states in silicon stressed at 770 °C in compression have been studied by capacitance transient spectroscopy on Schottky‐barrier structures. High‐resistivity n‐type samples are converted to p type. Low resistivity n‐type samples are compensated but recover upon annealing. A large variety of defect states are observed with prominent features at E (0.68) after deformation. The spectra simplify upon annealing at 900 °C to two dominant states, E (0.38) and H (0.35).

A new method is described for determining the energy of emitting centers in an interface‐state continuum independently of the emission rate in transient‐capacitance measurements on MIS structures. Deep‐level transient spectroscopy (DLTS) is performed in the double‐correlation mode to analyze the energy profile of a continuous interface‐trap distribution. With this method, DLTS can be used to evaluate interface‐state distributions with energy‐dependent capture cross sections, and the extraneous effects of bulk defect levels in the semiconductor are minimized. Experimental results are presented for electron traps at the Si‐SiO2 interface.

Deep‐level transient spectroscopy (DLTS) has been used to determine the activation energy and spatial distribution of the electron traps introduced n‐type silicon implanted with 5×1010Se ions/cm2 at 800 keV. Radiation damage levels were demonstrated to be present up to a 600 °C anneal. After 700 °C anneal, two deep levels were found at Ec−0.225 eV and Ec−0.485 eV. The in‐depth distributions of the Ec−0.225 eV level after 600 °C anneal and of the two levels after the 700 °C anneal were determined. So, it was found that selenium is a fast diffuser and that each implanted Se ion forms one trap with two levels.

Deep‐level transient spectroscopy experiments, performed on 31P+‐implanted and laser‐annealed silicon, have shown that the defect concentration is considerably reduced when a conventional thermal annealing is performed before the laser treatment. A model is presented which explains the origin of the defects.