The Influence of Materials of Electrodes of Sensitized Solar Cells on Their Capacitive and Electrical Characteristics

Russian Physics Journal - An estimation is made of the internal capacitance of sensitized solar cells (SSCs) manufactured by the method of extraction pyrolysis. The structures under study are...     

Synthesis, crystal structure, and luminescent properties of a silver(I) perrhenate complex with phenazine

The silver complex with phenazine [Ag(Phz)₂(H₂O)]ReO₄ (Phz is C₁₂H₈N₂) has been synthesized, and its crystal structure has been determined. The crystals are triclinic: space group $P\bar 1$ , a = 9.587(1) Å, b = 10.875(1) Å, c = 11.668(1) Å, α = 104.98(1)°, β = 103.87(1)°, γ = 92.94(1)°, V = 1132.6(2) ų, Z = 2, ρ_calc = 2.160 g/cm³. The structure is composed of the [Ag(Phz)₂(H₂O)]⁺ silver cationic complexes and ReO ₄ ^? anions. The Ag⁺ ion is coordinated by two nitrogen atoms of independent phenazine molecules and the water oxygen atoms and has a T-shaped coordination (Ag-N_av 2.223 Å, Ag-O_w 2.498(8) Å). Phenazine, being an electron-donor ligand, forms columns due to π-π stacking interaction between the aromatic groups. The water molecules form hydrogen bonds with the oxygen atoms of water molecules of neighboring complexes and with oxygen atoms of the ReO ₄ ^? anions.     

Coordination molecular compounds of cadmium(II) iodide with dimethylpyridines

The reactions of CdI₂ with dimethylpyridines (Me₂Py is C₇H₉N) afford complexes CdI₂(2,3-Me₂Py)₂] (I), [CdI₂(2,6-Me₂Py) (II), and CdI₂(3,5-Me₂Py)₂ (III). The structures of compounds I and II are determined. The crystals of complex I are orthorhombic, space group Pbca, a = 7.930(1) Å, b = 15.537(1) Å, c = 29.943(1) Å, V = 3689.1(5) ų, ρ_calcd = 2.090 g/cm³, Z = 8. The crystals of complex II are monoclinic, space group C2/c, a = 14.784(1), b = 11.991(1), c = 17.711(1) Å, β = 90.39(1)°, V = 1081.1(2) ų, ρ_calcd = 2.908 g/cm³, Z = 4. The structure of compound I is built of discrete neutral complexes [CdI₂(2,3-Me₂Py)₂]. The Cd polyhedron is a distorted tetrahedron (Cd-I 2.289–2.295, Cd-N 2.708–2.734 Å, angles N(I)CdN(I) 103.1°-114.8°). Polymer chains [CdI₂(2,6-Me₂Py)]_∞ extended along the direction [100] are observed due to the bridging iodine atoms in structure II. The Cd polyhedron is a trigonal bipyramid containing iodine atoms at the axial vertices (Cd-I_aks 3.040 Å) and two iodine atoms and the nitrogen atom of the Me₂Py ligand in the equatorial plane Me₂Py (Cd-I_eq 2.840 Å, Cd-N 2.309 Å). The compounds in the solid state are photoluminescent.     

A complex of cadmium(II) iodide with 4-cyanopyridine: Synthesis,crystal structure,and luminescent properties

The complex [CdI₂(4-CNPy)₂] (I) was obtained by a reaction of CdI₂ with 4-cyanopyridine (4-CNPy, C₆H₄N₂) and structurally characterized (CIF file CCDC no. 983377). The crystals of complex I are monoclinic, space group C2, a = 24.698(5) Å, b = 4.127(1) Å, c = 7.597(2) Å, β = 96.05(1)°, V = 770.0(3) ų, ρ_calcd = 2.477 g/cm³, Z = 2. In structure I, iodine atoms serve to unite complex molecules into the polymer chains [CdI₂(4-CNPy)₂]_∞ along the direction [010]. The Cd(1) atom lying on a twofold axis has a slightly distorted octahedral environment made up of four bridging iodine atoms and two nitrogen atoms of two ligands 4-CNPy (Cd-I_av, 2.947(2) and Cd-N(1), 2.410(6) Å). Within each chain, cadmium atoms are spaced apart at 4.13 Å. Complex I exhibits photoluminescence.     

Synthesis and photoelectrochemical properties of cyclometallated ruthenium(II) complex

A new ruthenium complex, (4-carboxy-1,10-phenantroline-7-carboxylate)(4,7-dicarboxy-1,10-phenantroline)(2-phenylpyridino-²C,N) ruthenium(II), was obtained for the application as a sensitizer in photoelectrochemical converters (PECC). Electrochemical and spectral characteristics of the compound were studied. It was found that the illumination of PECC with AM 1.5 100 mW/cm² solar spectrum simulator provides short circuit current density of 3.9 mA cm^?2 and broken circuit voltage of 0.47 V. PECC efficiency is 1.4% at fillfactor 76%. The lifetimes of charge carriers (electrons) and their transit time determined by modulation spectroscopy were found to be 28 and 4 ms, respectively.     

Cadmium Iodide Complex with 4-Aminomethylbenzoic Acid: Synthesis,Crystal Structure,and Luminescent Properties

[СdI₂(4-АmbaH)₂] · H₂O has been synthesized by the reaction between CdI₂ and 4-aminomethylbenzoic acid (4-AmbaH) in an aqueous solution. According to X-ray diffraction data, a 4-AmbaH aromatic molecule crystallizes in the form of a zwitterion with protonation of the NH ₃ ⁺ amino group and deprotonation of the carboxylate group, which is chelately coordinated to the Cd²⁺ ion. In addition to two iodine atoms, the Cd²⁺ atom located on the double crystallographic axis is coordinated to the chelate carboxylate O(1) and O(2) atoms of two crystallographically equivalent ligands 4-AmbaH. The octahedral geometry of the Cd²⁺ ion is strongly distorted due to the chelate addition of 4-AmbaH. The chelate coordination of COO–groups is confirmed by IR spectroscopy data. The complex has luminescent properties.     

Investigation of Electrophysical Properties of ITO Films

Russian Physics Journal - The results of a study of the electrophysical characteristics of ITO films obtained by magnetron sputtering are presented. It is shown that a significant increase in the...     

Silver complexes with 2-amino-4-methylpyrimidine: Synthesis, crystal structure, and luminescent properties

Reactions of AgReO₄ and AgCH₃SO₃ with L = 2-amino-4-methylpyrimidine (Ampym, C₅H₇N₃) in a ratio of 1: 2 in acetonitrile gave the complexes [AgL₂(ReO₄)] (I) and [AgL₂(CH₃SO₃)] (II). Their structures were determined. The crystals of complex I are monoclinic, space group C2/c, a = 5.985(1), b = 3.465(1), c = 19.071(1) Å, β = 96.52(1)°, V = 1527.0(3) ų, ρ_calcd = 2.507 g/cm³, Z = 4. The crystals of complex II are orthorhombic, space group Pbca, a = 14.784(1), b = 11.991(1), c = 17.711(1) Å, V = 3139.7(4) ų, ρ_calcd= 1.782 g/cm³, Z = 8. Structure I shows discrete cationic complexes [AgL₂]⁺. The silver atom is virtually linearly coordinated to two N atoms of crystallographically equivalent ligands L (Ag-N, 2.156(4) Å; the angle NAgN, 174.7(4)°). The complex cations are united into zigzag chains through the hydrogen bonds N-H...N. The resulting chains are linked by the hydrogen bonds N-H...O to uncoordinated perrhenate anions to form 2D supramolecular layers. In structure II, the Ag⁺ ion is coordinated by two crystallographically non-equivalent ligands L in a distorted linear fashion: Ag(1)-N(1), 2.166(7) Å;Ag(1)-N(4), 2.181(6) Å; the angle NAgN, 157.2(2)°. The anions CH₃SO₃ ^? are weakly linked to the Ag⁺ ions (Ag...O 2.72 Å) and are hydrogen-bonded to the complex cations [AgL₂]⁺, uniting them into supramolecular ribbons.     

Estimation of kinetic parameters for the phase change memory materials by DSC measurements

The non-isothermal method for estimating the kinetic parameters of crystallization for the phase change memory (PCM) materials was discussed. This method was applied to the perspective PCM material of Ge₂Sb₂Te₅ with different Bi contents (0, 0.5, 1, 3 mass%) for defining the kinetic triplet. Rutherford backscattering spectroscopy and X-ray diffraction were used to carry out elemental and phase analysis of the deposited films. Differential scanning calorimetry at eight different heating rates was used to investigate kinetics of thermally induced transformations in materials. Dependences of activation energies of crystallization (E _a) on the degree of conversion were estimated by model-free Ozawa–Flynn–Wall, Kissinger–Akahira–Sunose, Tang and Starink methods. The obtained values of E _a were quite close for all of these methods. The reaction models of the phase transitions were derived with using of the model-fitting Coats–Redfern method. In order to find pre-exponential factor A at progressive conversion values, we used values of E _a already estimated by the model-free isoconversional method. It was established that the crystallization processes in thin films investigated are most likely describes by the second and third-order reactions models. Obtained kinetic triplet allowed predicting transition and storage times of the PCM cells. It was found that thin films of Ge₂Sb₂Te₅ + 0.5 mass% Bi composition can provide the switching time of the phase change memory cell less than 1 ns. At the same time, at room temperature this material has a maximum storage time among the studied compositions.