Bulk non-radiative recombination reduction in nGaAs due to an annealing under Ga-Al melt

It is shown by microcathodoluminescence and electron beam induced current investigations that efficiency of radiative recombination and the values of hole diffusion lengths in nGaAs substrate increase (up to L_p ∽ 5 μm) due to an annealing under Ga Al melt. The values of the annealing critical temperature exceeding of which leeds to bulk non-radiative recombination drop as well as optimal values of annealing temperature and duration are determined. In pAlGaAs–(p-n)GaAs solar cells based on annealed substrates the values of open circuit voltage U_oc = 1.16 – 1.18 V under 500-fold concentrated solar radiation as well as values of photocurrent comparable with the best results of solar cells with epitaxial nGaAs are achieved.     

Diffusion of iodine in lead telluride

By using the non-stationary thermal-probe method, investigations were carrieed out on the distribution of the coefficient of thermal electromotive force along the depth of monocrystals of lead telluride, subjected to isothermal saturating annealing in vapours of alloying compositions. The alloying composition consisted of powdered lead telluride, synthesized by the iodide method, and contained elevated concentration of the metallic component and iodine. The PbTe monocrystals were obtained from the vapour phase and had a natural cut. The results of the investigations testify to considerable changes in the concentration of the electrically active proper defects within the entire volume of the crystals, this being obviously connected with diffusion of vacancies from the crystal volume.     

Influence of an ambipolar field and target boundary blurring on transition radiation from fast electrons of laser plasma

It is shown that the blurring of the rear side of a thin laser target leads to a decrease in the intensity of higher harmonics in the spectrum of coherent transition radiation and that the scale of the boundary inhomogeneity can be estimated from the amplitude ratio of harmonics. Deceleration of the electron flow in an ambipolar electric field at the rear boundary of a target leads to a decrease in the intensity of lower harmonics in the spectrum of coherent transition radiation, and the strength of the ambipolar field can be estimated from the amplitude ratio of harmonics. A change in the permittivity of a dielectric laser target with frequency can lead to an increase in the intensity of some harmonics in the spectrum due to the Vavilov-Cherenkov mechanism.     

Production of Pure Hydrogen Peroxide Solutions in Water Activated by the Plasma of Electrodeless Microwave Discharge and Their Application to Control Plant Growth

A method for the production of pure solutions of hydrogen peroxide during water activation by the plasma of electrodeless microwave discharge has been developed. It is shown that activated water has a pronounced effect on agricultural plants, being a non-toxic and chemically pure regulator of biological activity. In particular, the treatment of seeds of agricultural plants with activated water solutions can improve their drought resistance.

     

Metal–Insulator Phase Transition in Tungsten-Doped Vanadium Dioxide Thin Films

Physics of the Solid State - The electrical conductivity of thin polycrystalline V(1 – x)WxO2 has been studied in a wide temperature range, which covers the regions of both...     

X-Ray Diffraction Study of New Organic Compound n-Tol3Sb[OC(O)CH=CHPh]2

Crystallography Reports - The bis[(2E)-3-phenylprop-2-enoate]-tris(п-tolyl)antimony n-Tol3Sb[OC(O)CH=CHPh]2 complex is obtained as a result of interaction of tri-n-tolylantimony, hydrogen...     

Comparison of the Effective Potentials of Ultrawideband Combined and Helical Antennas

Russian Physics Journal - Comparative experimental investigations of combined and helical ultra-wideband antennas are performed. The antennas are optimized to be excited by the 1 ns bipolar voltage...     

Effect of the Solvent on the Coordination of Pyridine Derivatives with Zn Tetraphenylporphine

The coordination of zinc(II) tetraphenylporphine with pyridines was studied by electronic spectroscopy. Linear correlations were found between the thermodynamic and kinetic parameters of coordination in different solvents. The effect of the solvent on the stability constants of the complexes and the thermodynamics of complex formation are discussed.     

Tomographic probability representation for quantum fermion fields

Tomographic probability representation is introduced for fermion fields. The states of the fermions are mapped onto the probability distribution of discrete random variables (spin projections). The operators acting on the fermion states are described by fermionic tomographic symbols. The product of the operators acting on the fermion states is mapped onto the star-product of the fermionic symbols. The kernel of the star-product is obtained. The antisymmetry of the fermion states is formulated as a specific symmetry property of the tomographic joint probability distribution associated with the states.