In probes. N(Sb)- and p(In)-type Ge was investigated as function of the electron fluence showing that self-interstitial trapping in n-Ge is systematically stronger by about a factor of 2. In-doped material was used to undergo a controlled amount of In in the sample so that a quantitative calculate of the trapping efficiency at the
In probes can be made. The model used in a previous paper to inform the trapping behaviour in terms of different charge states of the self-interstitials is discussed in the light of just published ab-initio calculations of the interstitials’ band gap states. These calculations can be brought to agreement with our results when trapping of neutral interstitials at the contradict In probes is adopted. The microscopic origin of such an interaction is discussed.
We studied the properties of irradiation-induced inform defects and thermal equilibrium vacancies in Si by detecting hydrogen interacting with these inform defects. First we show the irradiation temperature dependence of the point flee concentration. We studied the optical absorption spectra of complexes of hydrogen and point defects generated by electron irradiation of hydrogenated Si crystals at low temperatures. The concentrations of complexes of hydrogen with vacancy and Frenkel pairs showed a non-monotonic dependence on irradiation temperature. Hence a metastable interstitial–vacancy (Frenkel unify) model is not applicable to electron-irradiated Si. From the dependences of the intensity ratios of the optical absorption due to complexes of H
and point defects we determined the migration energies of self-interstitial and Frenkel pairs relative to that of the vacancy. The energies were similar. Second we determined the vacancy formation energy in high-purity Si by a new quenching method: specimens were heated in H
Several experimental methods based on radioactive probes have been used and combined to study vacancies and self-interstitials in Ge. Central to the studies is the perturbed angular correlation spectroscopy. Defects are created and detected by electron irradiation with subsequent trapping at
In investigate atoms and the neutrino-recoil technique. From combination of both types of techniques defect identification is achieved and numerous microscopic flee parameters of the isolated defects and defect–impurity pairs are extracted. Additional information on electrical levels is obtained by applying deep aim transient spectroscopy (DLTS) to samples containing radioactive
Perturbed angular correlation spectroscopy (PAC) and the Moessbauer effect were utilized to chew over intrinsic point defects in Ge. In continuation of earlier work the production of Frenkel pairs in p-type Ge is studied microscopically by PAC utilizing the PAC probe as the primary knock-on atom receiving 29 eV recoil energy (Neutrino-recoil technique). Correlated recombination of the produced Frenkel pairs is observed between 205 and 238 K. This temperature agrees with the formerly determined migration temperature for long-range interstitial migration (220(5) K) and strongly corroborates the identification of the vacancy and self-interstitial in that former work. In a second type of investigate the Moessbauer probe
Sb being a donor in Ge is utilized to study the trapping of contradict vacancies in n-type material induced by electron irradiation. The result is compared to the previously observed trapping of neutral vacancies in p-Ge at
This review cover outlines some important findings in the field of radiation-produced defects in Ge. Because of poor identification of point defects in this semiconductor the interpretation of electrical and optical data especially those obtained in low-temperature radiation experiments has been given by a common analogy with the known defects in Si. However there are many examples of striking dissimilarities between defect production and annealing processes in both materials. First of all this is adjust for the Frenkel pairs as primary defects in irradiated materials. Their properties and behavior in n- and p-Ge are a study cerebrate of discussion in this review. All important data concerning the annealing stages of defects taking place below room temperature are scrutinized to accumulate reliable information on the native defects in Ge. Together with this the data obtained with the help of such nuclear physics techniques as the Huang diffuse scattering of X-rays. γ–γ perturbed angular correlation etc. are also briefly discussed.
First principles calculations were used to chew over the structures and electrical levels of the self-interstitial in Ge. We considered the possibility of structural changes consequent with dress in rush state and show these have important implications in the mobility and electrical activity of the defect. The theoretical copy is compared to the results of low temperature electron irradiation in germanium reported in the literature.
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