The paper presents the results of a study on the distribution of lithium in a solid-state thin-film lithium-ion battery using the Rutherford backscattering spectrometry (RBS) method. The analysis employs He+ ions with an energy of 1.8 MeV, scattered at an angle of 165° with normal incidence to the surface. Based on the energy loss of scattered ions, we determine the concentration of Li ions in the battery layers in both charged and discharged states. The study shows that the Li-concentration values obtained through the RBS method and the galvanostatic-measurement method coincide, provided that the specific stopping cross section for lithium εLi in the anode layer is half of that in the single-element substance.

The chemically inert luminophore, the chemiluminescence enhancer 1,10-phenanthroline-tris(thenoyl-trifluoroacetonate) of trivalent europium, increases the intensity of light emission by an order of magnitude during the initiated oxidation of lipid samples of vegetable origin (sunflower oil). The introduction of a light enhancer into the chemiluminescent system leads to a change in the kinetic profile, removing the characteristic peaks on the kinetic curves at the end of the induction period of the oxidation process, but without changing the induction period itself. Using mathematical computer modeling based on a kinetic scheme of 23 elementary reactions, it is shown that the observed kinetic behavior can be rationalized by a disproportionate increase in the quantum yields of chemiluminescence derived from different electronically excited products (light emitters) formed during the oxidation process.

The electrochemical characteristics of solid-state thin-film lithium-ion batteries with two different structures: Ti/Anode/LiPON/LiCoO2/Ti (with an anode) and Ti/LiPON/LiCoO2/Ti (anode-free) are intercompared. Si@O@Al composite anode with thicknesses of 154 and 15 nm, as well as pre-lithiated LixSi@O@Al composite with a thickness of 192 nm, were used as anodes. In anode-free batteries, the lithium anode was formed by the in-situ method. Batteries with 154 nm-thick Si@O@Al and LixSi@O@Al anodes have good cyclability due to their moderate volume change during lithium-ion insertion/extraction and reliable adhesion to the LiPON solid electrolyte. These batteries are promising in terms of high energy density due to the lithium anode in-situ formation, although they have poor cycling performance due to peeling of the upper current collector. The introducing of a Si@O@Al thin film with a thickness of 15 nm between the LiPON and the current collector allows maintaining the high energy density that is inherent in batteries with lithium anodes, while also improving their cyclability.

The results of measuring the charge-discharge characteristics of solid-state thin-film lithium-ion batteries with a nanocomposite anode based on a-Si(Al) solid solution are presented. The charging characteristics of batteries have a feature in the form of a step on the smooth branch of the charge curve. It is shown that the appearance of the step is associated with the compensation of a-Si(Al) and the change from hole to electron conductivity due to lithiation of the electrode during charging. As a result of lithiation, the electron over-barrier current becomes the main component of the charging current. To maintain a galvanostatic charge mode, the potentiostat increases the voltage by the height of the potential barrier, which leads to the appearance of a step on the charging curve. The impedance of a solid-state thin-film lithium-ion battery of the LiCoO2–LiPON–Si@O@Al electrochemical system was measured in the temperature range from –20 to 50°C. A structural model of the accumulator is proposed and the parameters of the structural elements of the model are calculated which provide the best fit for experimental Nyquist diagrams. The obtained values of the electrodes’ resistivity are orders of magnitude higher than the results of direct measurements and data from literary sources. According to the IV-characteristics obtained by cyclic voltammetry the high resistance of the electrodes is due to the metal-semiconductor contact and the varistor effect of the electrode material. The results obtained make significant adjustments to the interpretation of the impedance spectra and structural models of solid-state lithium-ion batteries based on semiconductor materials.

Crystalline texture, microstracture and resistivity of ion irradiated 12–41 nm Ti films are investigated. Ion bombardment was carried out in Ar plasma by applying negative bias 20–30 V to the films. It is found that this treatment leads to the formation of [100] texture in films having initially mixed [100] + [001] texture. The less the film thickness and the higher the bias the less treatment time is required for the [100] texture formation. Ion irradiation of 12 and 22 nm films using bias 30 V leads to the increase of interplanar distances in surface normal direction by 3

The purpose of this work is to study the characteristics of the junction between the titanium down conductor of a thin-film solid-state lithium-ion battery (a-Si) and a negative Si@O@Al nanocomposite electrode. The results of measuring the band gap of the Si@O@Al nanocomposite and the height of the Schottky barrier of the Ti–Si@O@Al junction are presented. The transmission and reflection spectra of Si@O@Al films and its main phases a-Si, a-SiOx, and a-Si(Alx) are studied. The band gap of Si@O@Al was determined by the Tauc method, which is 1.52 eV for a-Si and 1.15 eV for nc-Si. The IV characteristics of Ti‒Si@O@Al, Ti–a-Si, Ti–a-SiO0.8, and Ti–a-Si0.9(Al0.1) structures have been studied and the height of the Schottky barrier has been determined. The results obtained make it possible to estimate the Fermi energy of the nanocomposite and to interpret the hike in the SSLIB charging voltage as a result of the Al acceptor impurity compensation during lithiation. A change in the majority charge carriers in Si@O@Al leads to a decrease in the hole current and an increase in the density of the over-barrier electron current, as a result of which a step with a height of 1.5 V is formed on the charging curve.

AlN films are prepared by reactive magnetron sputtering at a floating potential and at the bias –15 V on the substrate. It is found that ion-assisted deposition facilitates the formation of fiber texture AlN (104). This result can be explained by generation of compressive stress in films due to ion bombardment and preferred orientation (104) is favored for stressed films minimizing the elastic strain energy. Ion-assisted deposition provides dense and large-grained structure of AlN films due to high adatom mobility.

The influence of nonuniformity properties of the LiCoO2 cathode film deposited by magnetron sputtering on the capacity of all-solid-state thin-film lithium-ion batteries (ASSLIB) was studied. It was found that the film nonuniformity corresponds to the magnetron plasma density distribution and the angular distribution of sputtered particles. The capacity distribution of the ASSLIB with LiCoO2 cathode depending on the distance to the substrate center was studied. The maximum capacity corresponded to the dense part of the toroidal region of the magnetron plasma. It was determined that the main causes of batteries capacity decline in the central part and on the edge of the substrate are the impurity phase of lithium cobaltate and the smaller thickness of the cathode layer, respectively.

The influence of low-energy ion bombardment on the texture and microstructure of an 80-nm-thick Pt film deposited at room temperature was investigated. The treatment was carried out in inductively coupled Ar plasma with a negative bias of 45–125 V applied to the specimens and an ion current density of 3.3 mA/cm2. As a result of a series of treatments at each bias, the film was thinned; after each treatment, its structural parameters were determined using X-ray diffraction and compared with those of Pt films 20–60 nm thick deposited under the same conditions. Treatment at 75–125 V led to a decrease in the average size of coherent scattering regions by 10–25%; in the 45 V mode, such a decrease was not observed. These results were explained by the formation and accumulation of radiation defects, the rate of their generation was lower at bias of 45 V. Film sputtering in all modes did not worsen the sharpness of the film texture.

The results from measuring the capacity of thin-film solid-state lithium-ion batteries (SSLIBs) Ti|Si@O@Al|LiPON|LiCoO2|Ti, Ti|Si@O@Al|LiPON|LixV2O5|Ti, and Ti|LiPON|LiCoO2|Ti at different charge currents are reported. It is shown that the dependence of the capacity on the current density Q(j) follows Peukert's law, which is characterized by a low value of Peukert's exponents in the region of low currents and a high value of the exponents in the region of high currents. Peukert's exponent for the anode-free cell remains constant through the entire range of current density variation. A model for SSLIB capacity based on the balance of ion (diffusion and drift) and electron currents is proposed. The model predicts a Q(j) dependence well approximating the experimental results and fitting Peukert's law. The model allows a qualitative interpretation of the change in the Peukert exponent with increasing current density, based on the effect of the charge current saturation.

We study the effect of low-energy ion bombardment on the texture and structure of an 80-nm-thick platinum film deposited at room temperature. The film is treated in an inductively coupled Ar plasma with a negative voltage of 45–125 V applied to the samples and an ion-current density of 3.3 mA/cm2. A series of treatments at each voltage results in thinning of the film; after each treatment, its structural parameters are determined by X-ray diffraction analysis and compared with the parameters of Pt films 20–60 nm thick deposited under the same conditions. The treatment at 75–125 V decreases the average size of the coherently diffracting domains by 10–25

Memristors (elements of nonvolatile electrically reprogrammable memory) based on electroformed open sandwich-metal–dielectric–metal (MDM) structures are fabricated using thin-film technology. Studies of the electroforming process and the features of the current–voltage characteristics (CVCs) after it was carried out for structures with various electrode materials showed that in the case of a tungsten anode, it was possible to minimize the probability of electrical breakdown during electroforming and subsequent operation of the memory elements. This is valid for any position of the anode in the MDM structure: both upper and lower. However, it is experimentally shown that tungsten is not the optimal material. The production of the anode from molybdenum retains all the advantages of the design with tungsten, and in addition, it leads to a noticeable decrease in the electroforming voltage, which can increase the reliability of this process. The results obtained can be used to optimize the design of the memory element.

The results of measuring the charge-discharge characteristics of solid-state thin-film lithium-ion batteries with a nanocomposite anode based on a-Si(Al) solid solution are presented. The charging characteristics of batteries have a feature in the form of a step on the smooth branch of the charge curve. It is shown that the appearance of the step is associated with the compensation of a-Si(Al) and the change from hole to electron conductivity due to lithiation of the electrode during charging. As a result of lithiation, the electron over-barrier current becomes the main component of the charging current. To maintain a galvanostatic charge mode, the potentiostat increases the voltage by the height of the potential barrier, which leads to the appearance of a step on the charging curve. The impedance of a solid-state thin-film lithium-ion battery of the LiCoO2-LiPON-Si@O@Al electrochemical system was measured in the temperature range from -20°С to 50°С. A structural model of the accumulator is proposed and the parameters of the structural elements of the model are calculated which provide the best fit for experimental Nyquist diagrams. The obtained values of the electrodes’ resistivity are orders of magnitude higher than the results of direct measurements and data from literary sources. According to the IV-characteristics obtained by cyclic voltammetry the high resistance of the electrodes is due to the metal-semiconductor contact and the varistor effect of the electrode material. The results obtained make significant adjustments to the interpretation of the impedance spectra and structural models of solid-state lithium-ion batteries based on semiconductor materials

The results on measuring the impedance of a solid-state thin-film lithium-ion battery of the Si@O@Al-LiPON-LiCoO2 electrochemical system in the temperature range from -20oC to +50oC are presented. A structural model is proposed and the parameters of its elements, providing the best fit for the experimental Nyquist diagrams, are calculated. It is shown that the main contribution to the internal resistance is made by the LiPON-LiCoO2 interface. Based on the temperature dependence of the LiPON solid electrolyte conductivity the activation energy of lithium is determined, which is in good agreement with the literature data. Keywords: Nanocomposite, lithium-ion battery, impedance spectroscopy, structural model, ionic conductivity.

The results of measuring the capacity of a thin-film solid-state lithium-ion battery (SSLIB) Ti|Si@O@Al|LiPON|LiCoO2|Ti at different charge currents are reported. It is shown that the dependence of the capacity on the current density follows the Peukert's law, which is characterized by a low value of the Peukert’s exponent in the region of low currents and a high value of the exponent in the region of high currents. A capacity model for a SSLIB based on the balance of diffusion and migration currents is proposed and the dependence of the capacity on the charge current is derived. The obtained dependence is well approximated by Peukert's law with an exponent of 1.39, which is intermediate between the exponents for lithium-ion batteries with liquid electrolyte and SSLIBs.

The results on measuring the impedance of a solid-state thin-film lithium-ion battery of the LiCoO2-LiPON-Si@O@Al electrochemical system in the temperature range from -20°С to 50°С are presented. A structural model is proposed and the parameters of its elements, providing the best fit for the experimental Nyquist diagrams, are calculated. It is shown that the main contribution to the internal resistance is made by the LiPON-LiCoO2 interface. Based on the temperature dependence of the LiPON solid electrolyte conductivity the activation energy of lithium is determined, which is in good agreement with the literature data.

The results of measuring the resistivity of thin-film structures Ti|Si@O@Al|Ti and Ti|LiCoO2|Ti by electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) are presented. It was found that, according to the EIS data, the resistance of Ti|Si@O@Al|Ti is three orders of magnitude higher than the CV data, which is due to the nonohmic nature of the metal-semiconductor junction and the varistor effect. It is shown that the Ti-LiCoO2 contact is ohmic, while the nonlinearity of the CVC is well described by the varistor effect. The results obtained are of importance for the interpretation of the impedance spectra of thin-film solid-state lithium-ion batteries based on semiconductor materials.

The results of measuring the charge-discharge characteristics of solid-state thin-film lithium-ion batteries with a nanocomposite anode based on a-Si(Al) solid solution are presented. The charging characteristics of batteries have a feature in the form of a step on the gentle branch of the curve. It has been suggested and substantiated that the appearance of the step is related to the gradual compensation and change of the a-Si(Al) hole conductivity to electronic one as the lithium concentration increases. As a result, the a-Si(Al)|Ti ohmic contact becomes rectifying, and the electrons participating in the Faraday process are forced to overcome the Schottky barrier. The potential growth required to maintain the galvanostatic charge regime appears as a step on the charge curve.

The formation of Janus-like particles of Pb-Sn during ion-plasma treatment of the surface of lead-tin telluride films was found. Pb0.6Sn0.4Te films 2 mu m thick were grown on (111) BaF2 substrates by molecular beam epitaxy. The ion-plasma treatment of the samples was carried out in a high-density low-pressure radio frequency inductively coupled plasma at an ion energy of 75 eV and 25 eV. The duration of the sputtering process was 240 s. The evolution of the film surface morphology and the formation of Pb-Sn Janus particles with nano-and submicron sizes have been studied.

i.v.uvarov@bk.ru Abstract. Microelectromechanical systems (MEMS) switches have outstanding working characteristics and a wide range of possible applications, but suffer from the lack of reliability. The main reason of failure is the degradation of metal contacts, which increases the on -resistance or leads to stiction. A proper choice of the contact material may solve the problem. In this work, the performance of Pt-Pt and Ru-Ru contacts is investigated. The study is performed using a recently proposed stiction-protected MEMS switch. The contact resistance and lifecycle in the cold switching regime are measured and compared.