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This work is devoted to the fabrication and investigation of electrical and photoelectric characteristics of p-SnS/n-InSe anisotype heterojunctions. Low-temperature spray pyrolysis technology was used to deposit SnS thin films on InSe crystal substrates. Based on the analysis of temperature dependences of forward and reverse I-V characteristics, the dynamics of changes in the energy parameters of the heterojunction were investigated. Theoretical models describing the behavior of the forward and reverse I-V characteristics are proposed. The value of the series and shunt resistances, as well as their influence on the I-V characteristics of the heterojunction, was determined. The value of the contact potential difference was estimated. The charge transfer was analyzed. The spectral dependence of the quantum efficiency of the pSnS/n-InSe heterostructure irradiated from the side of the SnS film in the photon energy range of 1.2÷3.2 eV was studied. [ABSTRACT FROM AUTHOR]

The conditions of application of thin semiconductor Mn2O3 films on p-InSe crystalline layered semiconductor substrates at a temperature of 623 K by the spray-pyrolysis method to create anisotypic heterojunctions n-Mn2O3/p-InSe were investigated. InSe is a promising material for photoelectronics. The use of the Mn2O3 film, which is transparent in the region of maximum photosensitivity of InSe, makes it possible to effectively exploit the optical properties of InSe in the fabrication of various semiconductor devices. The advantage of using layered semiconductors in the production of heterojunctions is that high-quality interfaces are obtained even with a significant discrepancy in the parameters of the crystal lattices of the starting materials. This significantly expands the choice of heterojunction materials. Electrical and photoelectric parameters of n-Mn2O3/p-InSe heterojunctions were measured and theoretical models describing them were proposed. The graphical dependencies of I-V characteristics, series resistance, height of the potential barrier and photosensitivity are constructed. It was established that these heterojunctions are photosensitive and have rectifying properties. Using the energy parameters of the starting materials, an energy diagram of the heterojunction was constructed, which allows for the analysis of physical processes in the obtained heterojunctions. Based on the temperature dependence of both direct and reverse I-V characteristics, the dynamics of changes in the energy parameters of the heterojunction with temperature, as well as the mechanisms of current flow through the heterojunction, are established. The spectral photosensitivity of the heterojunction was analyzed. [ABSTRACT FROM AUTHOR]

The results of investigation of the operating characteristics of the electrochemical system Li/Cu4Bi5S10 are presented. The mechanism of the current forming reaction is established. The impedance spectra of Li/Cu4Bi5S10 cells are investigated and analyzed at different depths of discharge. A model of the equivalent electrical circuit is proposed, and the coefficients describing the electrode reactions are estimated.

Photosensitive anisotypic CuFeO2/n-InSe heterojunctions were fabricated by the method of low-temperature spray pyrolysis. An aqueous solution of copper dichloride CuCl2∙2H2O and iron trichloride FeCl3∙6H2O was sprayed onto the InSe substrate heated to 623 K. As a result, p-type CuFeO2 films with a thickness of ~ 0.3 µm and a band gap of 2.6 eV were obtained. Contacts were formed using silver-based conductive paste. The I-V characteristics were studied at temperatures from 295 to 336 K. It was shown that the temperature dependence of the height of the potential barrier is linear. Based on the analysis of the temperature dependences of forward and reverse I-V characteristics, the dynamics of change of energy parameters was established and the role of energy states at the boundary of the heterojunction in the formation of the contact potential difference was clarified. The approximation of I-V characteristics was carried out within the framework of the model, which takes into account the influence of series and shunt resistances. The values of the diode coefficient, series and shunt resistances of the heterojunction were found. The mechanisms of formation of direct and reverse currents through the CuFeO2/n-InSe energy barrier were determined. The spectral dependence of the quantum efficiency of heterojunctions in the range of photon energies from 1.2 to 3.2 eV was studied. The effect of light absorption in heterostructure materials on its general photosensitivity was analyzed. The obtained results confirmed the promise of CuFeO2/n-InSe heterojunctions for photoelectronics. [ABSTRACT FROM AUTHOR]

Investigations of the crystalline structure and electrical properties of In2Se3<1 wt. %Mn> and In2Se3<6 wt. % Mn> crystals have been carried out. We have found formation of a substitutional solid solution for In2Se3<1 % Mn> single crystals as well as existence of two phases (In2Se3 and MnIn2Se4) in polycrystalline ingots In2Se3<6 % Mn>. Temperature dependences of the conductivities across (σ⊥C) and along (σ||C) the crystallographic c axis were measured in the range of 80 to 400 K. From the anisotropy σ⊥C/σ||C of conductivity temperature dependences of the energy barrier value ΔEδ between the layers were calculated for the crystals under investigations. [ABSTRACT FROM AUTHOR]

Influence of fast cooling on electrical properties of n-InSe single crystals is investigated for an ingot grown by the Bridgman method. Electrical characteristics and their anisotropy are investigated in the temperature range 80 to 410 K. It is found that fast cooling, as soon as crystallization is completed, of the ingot leads to an increase of the free electron concentration, conductivity along layers, and conductivity anisotropy, as well as to a decrease of the Hall mobility of carriers along layers. The theoretical analysis of the mobility of carriers has shown that space-charge regions underlie the effective mechanism of their scattering. [ABSTRACT FROM AUTHOR]

The electrical properties of nominally undoped and doped (0.1 wt % Cd, I, and Cu) In2Se3 single crystals have been studied in the range 80–400 K. Only iodine doping has been found to have a significant effect on the carrier concentration in In2Se3, raising it from 4.9 × 1017 to 1.6 × 1018 cm−3 at 300 K. The observed temperature variation of in-plane electron mobility is interpreted in terms of acoustic phonon and neutral impurity scattering. The three dopants have the strongest effect on the out-of-plane conductivity of In2Se3. [ABSTRACT FROM AUTHOR]

The electron spin resonance, magnetization, and dynamic magnetic susceptibility of In1 – xMnxSe layered crystals (x = 0.0125) are studied. It is found that two different impurity subsystems independently coexist in the crystalline layer and in the interlayer spacing of unannealed samples. In both subsystems, ferromagnetic exchange interaction occurs between the Mn ions in the temperature range 300–140 K, and antiferromagnetic interaction occurs in the range 140–77 K. At temperatures below 77 K, a three-dimensional ferromagnetic order emerges. © 2005 Pleiades Publishing, Inc. [ABSTRACT FROM AUTHOR]