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• STUDY OF RESISTIVE SWITCHING OF TRANSPARENT ZINC OXIDE MEMRISTIVE STRUCTURES FOR MACHINE VISION OF ROBOTIC SYSTEMS

  А.V. Saenko , К.А. Kozyumenko , I.А. Shikhovtsov , R. V. Tominov , V.А. Smirnov

  2026-02-27

  Abstract ▼

  The development of neuromorphic machine vision systems for robotic systems requires the creation of transparent memristive structures that combine optical transparency, stable bipolar resistive switching, and compatibility with crossbar array technology. A key challenge is to establish patterns in the influence of ZnO thin film deposition modes on their structural and electrical properties, which determine the characteristics of memristive structures. The aim of this study was to determine the optimal RF magnetron sputtering power for a ZnO ceramic target, ensuring the formation of transparent ITO/ZnO/ITO memristive structures with stable resistive switching, and to create a crossbar array based on these structures. ZnO thin films were deposited using RF magnetron sputtering at powers ranging from 25 to 100 W. Structural (SEM, AFM) and electrical (Hall effect) studies of the resulting ZnO films were conducted. Transparent ITO/ZnO/ITO memristive structures and a crossbar array of 16 structures with a cell size of 2000 × 2000 nm were fabricated on glass substrates using magnetron sputtering and lithography, and their current-voltage characteristics were measured. Increasing the magnetron sputtering power from 25 to 100 W resulted in an increase in the grain size from 12,8 to 35,7 nm and in the surface roughness of the ZnO films from 2,8 to 11,4 nm. At a sputtering power of 75 W, the charge carrier concentration in the ZnO films reached a maximum value of 2.7 × 1015 cm-3, which is necessary for stable resistive switching of the structure. The obtained ITO/ZnO/ITO memristive structures were shown to exhibit stable bipolar switching for 1000 cycles between the states HRS = 537,4 ± 26,7 Ohm and LRS = 291,4 ± 38,5 Ohm (HRS/LRS ratio ~ 1,8). The fabricated transparent crossbar array showed stable resistive switching for 20000 cycles (LRS = 13,8 ± 1,4 kOhm, HRS = 34,8 ± 2,6 kOhm, HRS/LRS ratio ~ 2,5). The obtained results can be used in the development of technological processes for the fabrication of transparent memristor crossbars for neuromorphic structures of machine vision in robotic systems

• STUDY OF THE MODES OF FORMING ZnO: Ga NANOCRYSTALLINE FILMS BY MAGNETRON SPUTTERING

  А. А. Geldash, L.E. Levenets, E.Y. Gusev, V.N. Dzhuplin

  2020-07-20

  Abstract ▼

  The main goal of this work is to study the modes of formation of thin nanocrystalline ZnO:
  Ga films by direct current magnetron sputtering. The main objective of the study is to obtain thin
  (~ 300 nm), transparent, conductive films with a resistivity value of less than 5 · 10-3 Ohm · cm,
  which can be used as contacts for nanostructures of photosensitive elements, as well as studying
  the technological parameters of magnetron sputtering equipment and metal oxide targets. The
  morphology of the resulting thin ZnO: Ga films was studied. As a result of the study, it was revealed
  that the surface of the films consists of individual crystals, united together during the deposition
  of the material. These crystals have pronounced faces and peaks. It was also revealed that
  with an increase in the power of a direct current source, the crystals on the film surface increase
  several times in proportion to the increase in power, and the film thickness increases due to anincrease in the speed of sputtering of the target material on the substrate. Further, the electrical
  characteristics of the obtained films were investigated and the dependences of the influence of the
  power (thickness) of the film on the carrier concentration, their mobility, and also resistivity were
  derived. Thus, it was revealed that with an increase in the film thickness from 320 nm to 340 nm, the
  mobility of current carriers increases from 3.027 cm2/(V·s) to 3.228 cm2/(V·s), and with an increase
  in the film thickness from 800 nm to 1200 nm of current carriers increases from 6.511 cm2/(V·s) to
  6.547 cm2/(V·s). With an increase in the film thickness from 320 nm to 340 nm, the concentration of
  current carriers decreases from 1.571·1020 cm– 3 to 1.489·1020 cm– 3, and with an increase in the film
  thickness from 800 nm to 1200 nm, the concentration of current carriers decreases from 2.481·1020
  cm-3 to 1.653·1020 cm-3. As the film thickness increases from 320 nm to 340 nm, the resistivity increases
  from 1.303·10-2 Ω·cm to 1.38 ·10-2 Ω·cm. and as the film thickness increases from 800 nm to
  1200 nm, the resistivity increases from 3.851·10-2 Ω·cm to 5.779·10-2 Ω·cm.

• STUDY OF THE OPTICAL PROPERTIES OF THIN LAYERS OF ZINC OXIDE ZnO OBTAINED BY THE SOL-GEL METHOD

  U.А. Maryina, D.L. Gazdinsky, О.М. Chapura, L. V. Mikhnev, Е.А. Bondarenko, R. V. Pigulev

  136-144

  2025-08-01

  Abstract ▼

  Currently, the actual direction is the search for functional layers for various optoelectronic
  devices. A promising candidate as a basis for many such structures is zinc oxide (ZnO), which
  combines a number of unique optical and photoelectric properties. However, the characteristics of
  ZnO thin films can vary significantly depending on the chosen synthesis method and specific production
  conditions. One of the varieties of the sol-gel method suitable for the synthesis of
  nanoscale films is the dip-coating method. The paper presents the results of the synthesis of thin
  films of zinc oxide on glass substrates by the method of vertical drawing from ZnO alcohol sol.
  The effect of the elongation rate on the structural and optical properties of synthesized ZnO films
  was studied using spectral ellipsometry and spectral photometry. By the method of spectral
  ellipsometry, it was found that the change in the rate of elongation significantly affects the thickness
  and porosity of the synthesized zinc oxide layers. The analysis of the obtained dependence of
  the film thickness on the pulling speed showed that in the vertical pulling method, the growth of
  zinc oxide on glass substrates can be realized in two modes: in capillary forces mode and in drying
  mode. At the same time, transmission spectra were measured for synthesized ZnO films by
  spectral photometry, the analysis of which showed the effect of the elongation rate on the position
  of the edge of fundamental absorption. It was found that the main cause of the resulting.