Thermally Stimulated Currents in Semiconductors: Analysis of Rate Equations for a Single-Level Model and Thermally Stimulated Currents in Si<P,Au>

Thermally stimulated currents (TSCs) in semiconductors are analyzed theoretically. The rate equations describing TSCs are solved numerically for various heating profiles, which makes it possible to evaluate the ionization energy, concentration, and capture cross section of traps. The slow and fast retrapping approximations are examined for an arbitrary heating profile. A new approach to TSC data processing is proposed: cleaning of a peak from the lower temperature peak by storing the preilluminated material in the dark at the relaxation temperature of the lower temperature peak. It is shown that heating (constant-rate or exponential) followed by isothermal holding makes it possible to determine the ionization energy of traps without knowing the retrapping mechanism. This approach is adapted for the case when the retrapping time is comparable to the carrier lifetime. Partially compensated silicon with impurity photoconductivity is prepared by doping with gold and phosphorus. It is shown that, using resonance photoexcitation, one can identify the nature (electron or hole) of traps and evaluate their ionization energy. The depths and capture cross sections of three trapping centers in Si were evaluated.     

Modification of the Properties of Paving Asphalts by Treatment of Vacuum Resid with Sulfur

Interest in utilization of elemental sulfur has increased sharply due to development of the large Astrakhan' gas—condensate field, stiffening of environmental requirements for sulfur content in petroleum products, and simultaneously the drop in demand for elemental sulfur on the world market. Research on modification of the properties of asphalts with elemental sulfur has been conducted in Russia for more than 30 years. However, the results of these studies are often contradictory.     

Providing with vitamins of river transport workers of the Western and Eastern Siberia and oil men of the Tyumen Region]

The investigation of providing with vitamins of river transport workers in Western and Eastern Siberia and of oil men in the Tyumen Region conducted in the summer period of 1984-1986 has revealed significant deficiencies of vitamins C, E, B1, B2, B6, A and carotene in them. Vitamin administration to the workers with "Undevitum" resulted in a significant improvement of their vitamin status that was expressed in elevation of their biochemical parameters and in diminution of the percentage of subjects with vitamin deficiencies.     

Special features of relaxation of metastable states induced thermally and by photoexcitation in (a-Si:H):P films

Kinetics of relaxation of metastable states that are induced thermally or by photoexcitation and cause an increase in dark electrical conductivity of (a-Si:H):P films is discussed. It is established that the relaxation is described by expanded exponential functions with the parameters τ and β depending differently on temperature in the cases of thermal excitation and photoexcitation. Thus, the relaxation of photo-induced states is characterized by a decrease in β with temperature, whereas the parameter β is almost temperature-independent for thermally induced states. It is shown that these dissimilar temperature dependences of β correlate with temperature variations of the half-width of annealing-energy distribution for these states. The observed features of relaxation of thermally induced and photo-induced metastable states are caused by different mechanisms of their formation. The origin of these states can be the same and related to activation of hydrogen-passivated phosphorus atoms.     

Effect of the Phase Composition and Local Crystal Structure on the Transport Properties of the ZrO2–Y2O3 and ZrO2–Gd2O3 Solid Solutions

Russian Microelectronics - The results of investigating the crystal structure, ionic conductivity, and local structure of the (ZrO2)1 –x(Gd2O3)x and (ZrO2)1 –x(Y2O3)x (x = 0.04, 0.08,...     

Water diffusion in Zr-containing fiberglass materials at room temperature

Diffusion of water into Zr-containing silica fiberglass materials was studied at room temperature by infrared spectroscopy. Several types of experiments were performed: (a) rehydration with H₂O of fiberglass materials previously calcined in air at 450°C and under vacuum at 180°C; (b) isotopic experiments for uncalcined fiberglass materials using D₂O with and without the presence of sodium. Water diffusion coefficients were determined in each case. It was suggested that the transfer of the protons and water molecules occurred by different mechanisms: the protons diffused through the hydroxyl groups via the relay mechanism like in liquid water, whereas water diffused more slowly in the form of molecular water.