"Technical Physics Letters"

Baranov, A. M.;Malov, Yu. A.;Tereshin, S. A.

doi: 10.1134/1.1261894pmid: N/A

Abstract A new system for a photoelectric converter is proposed, and its photoelectric properties are studied, using an n-CdO/a-C/p-Si heterostructure as an example. The distinguishing feature of the structure is that the broad-band insulating layer of SiO2 on the surface of the silicon is replaced by a narrow-band layer of amorphous carbon, while a layer of CdO is used as the upper electrode. It is shown that an increase of the short-circuit current because of impact ionization can be expected in such a heterostructure. The results of the paper show that it is worthwhile to use CdO films in practice as transparent electrodes.

Batyaev, I. M.;Kleshchinov, E. B.

doi: 10.1134/1.1261895pmid: N/A

Abstract A luminophor based on aluminosilicophosphate glass doped with erbium (III) and titanium (III) has been synthesized. It is shown that the erbium luminescence in this glass is efficiently sensitized by the titanium ions via the 4I13/2→4I15/2 channel (λ=1.538 μm). It is determined that the transport is by a dipole-dipole mechanism. The critical transport concentration is 0.032 M, and the critical transport distance is 1.95 nm.

Vrubel’, M. M.;Borzdov, V. M.;Komarov, F. F.

doi: 10.1134/1.1261896pmid: N/A

Abstract This paper discusses the question of how the size of the spacer layers affects the position and width of the bistability region in the current-voltage characteristics of tunnel resonance diodes. The current-voltage characteristics were calculated in terms of the self-consistent effective-mass approximation. Increasing the size of the spacer layers shifts the lower boundary of the bistability region upwards so that this region becomes narrower and then completely disappears.

Sidorov, V. G.;Drizhuk, A. G.;Sidorov, D. V.

doi: 10.1134/1.1261897pmid: N/A

Abstract This paper discusses the possibility of increasing the efficiency and reliability of radiation sources made from semiconductors with unipolar conductivity and operating in strong electric fields. To this end, the active region of the structure is fabricated in the form of alternating layers of different resistance, so that strong-field regions are spatially separated from luminescence-generation regions. The proposed idea is put into practice on M-i-n structures made from gallium nitride. The properties of fabricated LED structures are presented.

Popov, A. A.;Stepanov, M. V.;Sherstnev, V. V.;Yakovlev, Yu. P.

doi: 10.1134/1.1261898pmid: N/A

Abstract LEDs have been created that emit in the region of the fundamental absorption band of methane at a wavelength of 3.3 μm for fast-response gas analyzers. A continuous optical power of 0.13 mW (cw) is achieved, and the peak optical power is 2.2 mW (the pulsewidth is 50 0μs, and the inverse duty cycle is 1.6×102). The current dependence of the optical power on the pump-pulse parameters is studied, and the conditions are found under which the peak power of the radiation of the LEDs in the mid-IR region is maximized.

Grigor’ev, A. I.;Belonozhko, D. F.;Shiryaeva, S. O.;Shchukin, S. I.

doi: 10.1134/1.1261899pmid: N/A

Abstract This paper shows that, in an electrostatic field normal to the flat interface of two viscous electrically conductive liquids, an oscillatory instability of the interface with periodically increasing amplitude can be produced when the electrical conductivity of the upper liquid is substantially greater than that of the lower one. Results are obtained by numerical analysis of the dispersion equation.

Khvesyuk, V. I.;Khvesyuk, A. V.;Lyakhov, A. N.

doi: 10.1134/1.1261900pmid: N/A

Abstract This paper discusses the dynamics of the fusion products of the D-He3 reaction in a field-reversed configuration, with application to a reactor regime with a large value of the plasma β. It shows that, under the conditions in the Artemis-L design [H. Momota and Y. Tomita, J. Plasma Fusion Res. 69, 801 (1993)], the motion of protons with an initial energy of 14.1 MeV is strongly stochasticized. The confinement time of these particles and the energy transfer from the fusion products to the plasma are very small.

Dul’kin, E. A.;Gavrilyachenko, V. G.

doi: 10.1134/1.1261901pmid: N/A

Abstract Optical microscopy and acoustic emission have been used to study the phase transition in PbTiO3 crystals. It is established that the acoustic-emission activity depends on the angle between the normal to the interphase boundary and the direction of a uniform temperature gradient. It is shown that the orientation of the interphase boundary is determined by the post-growth defect system of the crystals.

Shtan’ko, V. F.;Chinkov, E. P.

doi: 10.1134/1.1261902pmid: N/A

Abstract It is established that the optical absorption in the hole and electron components of autolocalized excitons in BaF2 excited by a pulsed electron beam consists of a collection of overlapping bands with a half-width no greater than 0.1 eV. Simultaneous subexcitation with the stimulated emission of II–VI semiconductors made it possible to isolate three groups of bands, caused, by analogy with CaF2 [Phys. Solid State 39, 1060 (1997)], by different configurations of autolocalized excitons in the fluorite lattice. The process of radiative decay of autolocalized excitons in CaF2 and BaF2 when they are optically excited in the region of the electron component of the absorption has been detected. The spectral rate parameters of the radiation that appears during simultaneous subexcitation coincide with the characteristics of the radiation ascribed earlier to core-valence transitions. The photostimulated variation of the absorption spectra of autolocalized excitons is accompanied by selective variation of the luminescence spectra of autolocalized excitons, which also is evidence of their complex spectral content.

Budnikov, V. N.;Bulanin, V. V.;Vers, A. V.;Esipov, L. A.;Its, E. R.;Lashkul, S. I.;Petrov, A. V.;Tukachinskii, A. Yu.

doi: 10.1134/1.1261903pmid: N/A

Abstract Collective scattering of CO2-laser radiation is used to study the microturbulence of the plasma in the FT-2 tokamak when the current is rapidly raised, while the magnetic-field shear is varied appreciably. The experiment exhibited suppression of the plasma fluctuations, the appearance time of which was correlated with the transition of the discharge to the improvedconfinement regime. The resulting data are evidence that the suppression of the oscillations occurred predominantly in the central zone of the tokamak, and a suppression-extending phenomenon or hysteresis is detected. The evolution of the spectral characteristics of the fluctuations during the suppression is analyzed, using model calculations of the magnetic-field shear.