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The structure of CdTe–Sb2Te3 and CdTe–CdSb solid solutions (0–1019 Sb atoms cm–3) prepared by multistage solid-state synthesis from the elements has been studied. It has been found that the introduction of antimony Sb3+ and Sb3− into cadmium telluride leads to a decrease and increase in the unit cell volume, respectively. It has been shown that the crystal lattice parameters gradually change up to an antimony concentration of 1018 atoms cm–3 in both systems, whereas an increase in the antimony concentration above 1018 Sb atoms cm–3 is characterized by an abrupt change in the unit cell volume due to a significant change in the structure. The decay kinetics of current carriers has been studied by the time-resolved microwave photoconductivity method. It has been found that the introduction of antimony into CdTe in a threshold concentration (1018 Sb atoms cm–3) leads to an increase in the lifetime of photogenerated current carriers; this fact can be attributed to the formation of defect associates and the occurrence of a self-compensation process during doping. [ABSTRACT FROM AUTHOR]

A study is performed of the effect TiO2 nanoparticles have on the temperature dependence of the direct current conductivity of epoxy polymers. The value of direct current conductivity is determined by analyzing the frequency dependence of the complex permittivity in the 102–105 Hz range of frequencies. Two characteristic regions are found on the temperature dependence of direct current conductivity: the Vogel–Fulcher–Tammann dependence above the glass transition temperature (Tg), and the Arrhenius dependence below Tg, due apparently to a change in the mechanism of conduction after the freezing of ionic mobility at temperatures g. It is found the calculated energy of activation of the Arrhenius process changes upon raising the concentration of TiO2 nanoparticles. [ABSTRACT FROM AUTHOR]

Polycrystalline Cu2ZnSn(SхSe1– х)4 solid solutions have been prepared by a single-temperature method using elemental Cu, Zn, Sn, S, and Se. The chemical composition of the synthesized materials has been determined by X-ray microanalysis and their crystal structure and phase composition have been studied by X-ray diffraction and Raman spectroscopy. Using frequency-time-resolved microwave photoconductivity measurements, we examined the effect of sulfur and selenium content on photogenerated current carrier loss kinetics in the Cu2ZnSn(SхSe1– х)4 solid solutions. An increase in sulfur content has been shown to result in the formation of additional deep levels, capable of acting as electron acceptors. [ABSTRACT FROM AUTHOR]

Cu1 –x(In0.7Ga0.3)Se2 (0 ≤ x ≤ 0.30) copper-deficient solid solutions with the chalcopyrite structure have been synthesized and their unit-cell parameters have been determined as functions of composition. Their 78-K cathodoluminescence spectra show a band centered at 1.13 eV, which is most likely due to Cu2+ ⋅ VCu defect associates. Microwave photoconductivity data demonstrate that the defect associates act as electron traps, considerably reducing the lifetime of photogenerated current carriers. [ABSTRACT FROM AUTHOR]

It can be seen from the figure that the characteristic decay times of microwave photoconductivity increase on going from CuGaSe SB 2 sb to AgGaSe SB 2 sb . High-purity Ag SB 1- I x i sb Cu SB I x i sb GaSe SB 2 sb powders ( I x i = 0, 0.30, 0.64, 1) were obtained by solid-phase synthesis from elemental Cu, Ag, Ga, and S (purity 4N) in evacuated quartz ampoules. The XRD study of these samples (PANalitical Aeris, Cu-K SB sb radiation) showed that they are monophasic CuGaSe SB 2 sb -AgGaSe SB 2 sb solid solutions. [Extracted from the article]

It can be seen from the figure that with a decrease in the copper content in the samples, the characteristic decay time of microwave photoconductivity decreases. 1 shows the normalized decays of microwave photoconductivity in Cu SB 2 sb CdSnS SB 4 sb (curve I 1 i ) and Cu SB 1.6 sb CdSnS SB 4 sb (curve I 2 i ) powders. Table 1 shows summary experimental data on the characteristic decay times of the "fast" and "slow" components of microwave photoresponse in the Cu SB 2- sb CdSnS SB 4 sb (0 <= <= 0.4) powders. [Extracted from the article]