A study is performed of the effect TiO 2 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 10 2 –10 5 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 ( T g ), and the Arrhenius dependence below T g , due apparently to a change in the mechanism of conduction after the freezing of ionic mobility at temperatures < T g . It is found the calculated energy of activation of the Arrhenius process changes upon raising the concentration of TiO 2 nanoparticles.

Literature on new semiconductors, quaternary copper compounds Cu2AIIBIVS(Se)4 where A = Mg, Ca, Sr, Ba, Fe,Ni,Co, Cd, or Cr; and B = Sn, Pb, Si, Ge, Ti, Zr, or Hf, is reviewed. Compounds of this family can substitute for the more abundant Cu1 – δIn1 – xGaxSe2 (CIGS) chalcopyrites and Cu2 – δZnSnS4 – ySey (CZTSSe) kesterites used for thin-film solar cells. The review summarizes evidence from the world literature on optical and electrophysical properties of those compounds, the specifics of their manufacturing and solar cells based on them.

The kinetics of photodissociation of ferrocene in bisphenol A dicyanate oligomer is studied using photospectroscopy. Thermograms of bisphenol A dicyanate oligomer polymerization in the presence of photodissociated ferrocene are obtained. Kinetic calculations and analysis of the thermograms lead to the conclusion that systems based on bisphenol A dicyanate oligomer and ferrocene may find application in 3D printing.

By solid-phase synthesis from elemental Cu, Ni, Sn, and S samples Cu 2-delta NiSnS 4 (0≤delta≤0.2) was prepared. The parameters of their crystal lattice have been refined. The lifetimes of photogenerated current carriers in Cu 2-delta NiSnS 4 were estimated for the first time by the contactless time-resolved microwave photoconductivity method. This times turned out to be tau~7 ns, which is comparable with the literature data for the times in kesterites CZTS. Herewith, in kinetics of loses of photogenerated cureent carriers is observed predominance of bimolecular recombination processes over capture processes. Keywords: Cu 2-delta NiSnS 4 , onequilibrium current carriers, lifetimes, kinetics.

The kinetics of processes related to the dissociation of ferrocene in bisphenol А dicyanate oligomer under UV light is studied. Using the kinetic data rate constants are calculated and assumption regarding the mechanism of photochemical reactions occurring in the system is made. The photodissociation of ferrocene under medium-wave UV irradiation becomes possible due to the presence of cyanate ester iminocarbamate derivatives in the oligomer mixture.

The kinetic studies of photodissociation of ferrocene in the oligomer of bisphenol A dicyanate were done using photospectroscopy. Thermograms of polymerization of the bisphenol A dicyanate oligomer in the presence of photodissociated ferrocene were also obtained. Based on kinetic calculations and analysis of thermograms, conclusion has been made regarding the possibility and promising use of a system based on the oligomer bisphenol A dicyanate and ferrocene for 3D printing.

By solid-phase synthesis from elemental Cu, Ni, Sn, and S samples Cu2 - δNiSnS4 was prepared . The parameters of their crystal lattice have been refined. The lifetimes of photogenerated current carriers in Cu2 - δNiSnS4 were estimated for the first time by the contactless time-resolved microwave photoconductivity method. This times turned out to be τ ≈ 7 ns, which is comparable with the literature data for the times in kesterites CZTS. Herewith, in kinetics of loses of photogenerated cureent carriers is observed predominance of bimolecular recombination processes over capture processes.

Cu 2 – x Zn 1 + 0.5 х SnS 4 copper-deficient solid solutions with the kesterite structure have been synthesized and their unit-cell parameters have been determined for the first time as functions of composition in the range 0 < x ≤ 0.45. The 78-K cathodoluminescence spectra of the Cu 2 – x Zn 1 + 0.5 х SnS 4 (0 < x ≤ 0.30) solid solutions show a band centered at 1.315 eV, which is most likely due to Zn 2+ V Cu associates—predominant defects. The luminescence of the Cu 2 – x ZnSnS 4 solid solutions is due to Сu 2+ V Cu predominant defects.

CuAlxIn1−xSe2 solid solutions with a chalcopyrite crystal structure were synthesized from elemental Cu, In, Al and Se. The dependence of their unit cell parameters on x in a range of 0 < x ≤ 0.30 was determined. The band with a maximum at 1.320 eV in the cathodoluminescence spectra of CuAlxIn1−xSe2 solid solutions at 78 K was most likely due to defects formed upon mutual substitution of atoms between the copper and aluminum–indium sublattices in the chalcopyrite structure.

The effect of the annealing temperature in the presence of mixtures of cadmium chloride and cadmium iodide of different compositions on the electrophysical properties of CdTe thin films is studied. This process, in which, as a rule, cadmium chloride is used, is called activation. It allows us to significantly improve the efficiency of solar cells based on CdTe. It is found that the temperature of this process can be reduced from 450 to 300°C by replacing CdCl2 with a mixture of the composition of ~60 mol % CdCl2 to ~40 mol % CdI2.

By solid-phase synthesis, macrocrystalline Cu2 − δZn2 − xSnxS4 − ySey monograin powders have been prepared, the chemical composition of which was shown by XRD and Raman spectroscopy to be different in powder fractions of different sizes formed during the synthesis. The influence of synthesis conditions on the decay kinetics of photogenerated charge carriers in different fractions has been studied using the frequency–time-resolved microwave photoconductivity method. The characteristic photoresponse half-life, τ1/2, increased with increasing grain size. The smallest values of the lifetime were observed for the fraction with sizes of 50–70 μm (τ1/2 <5 ns), and the largest values were for the fraction with a grain size of 70–90 μm (τ1/2 ~ 12 ns).

AbstractThe kinetics of the photoresponse of microwave photoconductivity (9 GHz, TE_101-type cavity) on excitation by laser light pulses with a wavelength of 337 nm and a duration of 8 ns in copper-deficient Cu_1 –_ x (In_0.7Ga_0.3)Se_2 (CIGS) (0 < x ≤ 0.4) solid solutions with the chalcopyrite structure is investigated in a wide light intensity range. With an increase in the laser radiation density to ~5 × 10^14 photon/cm^2 per pulse, the photoresponse acquires, along with the previously revealed skin effect, the effect of the filling of traps created by V _Cu vacancies and Cu^+2 · V _Cu defect associates, the concentration of which increases with a decrease in x in the CIGS formula.

The crystallographic parameters of CuIn2Se4 possessing a CdAl2S4-type crystal structure and Cu(In1−xGax)2Se4 solid solutions based on it were determined. The evaluated magnetic properties confirmed the presence of copper(II) in the crystal lattices of CuIn2Se4 and Cu(In0.7Ga0.3)2Se4 solid solutions, which are semiconductors with band gaps of ≥1.08 and ≥1.17eV (at 298K), respectively, found from their cathodoluminescence spectra.