The SiO₂ZrO₂ composite films were prepared by means of sol-gel technology and characterized by scanning electron microscopy, energy dispersive X-ray (EDX) analysis, and X-ray diffraction. The presence of the stable monoclinic ZrO₂ with an impurity of tetragonal phases is shown. The film surface is characterized by the presence of ZrOCl₂·6H₂O or ZrCl(OH)/ZrCl(OH)₂ grains. The crystallite size negligibly depends on the annealing temperature of the film and amount to 10–12 nm and 9–12 nm for the films thermally treated at 200 °C and 500 °C, respectively. The film’s resistance is rather sensitive to the presence of NO₂ impurities in the air at a low operating temperature (25 °C). Accelerated stability tests of the initial resistance showed high stability and reproducibility of the sensor based on the SiO₂ZrO₂ film thermally treated at 500 °C.

Silicon-carbon films have been deposited on silicon and Al₂O₃/Cr-Cu substrates, making use of the electrolysis of methanol/dimethylformamide-hexamethyldisilazane (HMDS) solutions. The electrodeposited films were characterized by Raman spectroscopy and scanning electron microscopy, respectively. Moreover, the nucleation and growth mechanism of the films were studied from the experimental current transients.

Silicon - carbon thin films were obtained on silicon substrate by using electrochemical deposition at room temperature and atmospheric pressure. Solution of electrochemical deposition was consisted of methanol or ethanol and hexamethyldisilazane ((CH₃)₃-Si-NH-Si-(CH₃)₃, HMDSN). It was shown that a type of electrolyte is strongly effect on maximum current density and the morphology of the deposited film.

In this study, we designed two types of gas-sensor chips with silicon–carbon film, doped with CuO, as the sensitive layer. The first type of gas-sensor chip consists of an Al₂O₃ substrate with a conductive chromium sublayer of ~10 nm thickness and 200 Ω/□ surface resistance, deposited by magnetron sputtering. The second type was fabricated via the electrochemical deposition of a silicon–carbon film onto a dielectric substrate with copper electrodes formed by photoelectrochemical etching. The gas sensors are sensitive to the presence of CO and CH₄ impurities in the air at operating temperatures above 150 °C, and demonstrated p- (type-1) and n-type (type-2) conductivity. The type-1 gas sensor showed fast response and recovery time but low sensitivity, while the type-2 sensor was characterized by high sensitivity but longer response and recovery time. The silicon–carbon films were characterized by the presence of the hexagonal 6H SiC polytype with the impurities of the rhombohedral 15 R SiC phase. XRD analysis revealed the presence of a CuO phase.

The SiO ₂ -ZrO ₂ composite films were prepared by means of the sol-gel technology from the tetraethoxysilane-based alcohol solution. To fabricate the SiO ₂ -ZrO ₂ gas sensors, a V -Cu-Cr was deposited via an interdigitated shadow mask onto other SiO ₂ ZrO ₂ -SiO ₂ -Si templates. The gas sensor was exposed to 40-1060 ppm concentrations of NO ₂ gas in ambient air. The sensor resistance is rather sensitive to the presence of NO ₂ impurity in air at low operating temperature (25°C). Accelerated stability tests of the initial resistance performed high stability and reproducibility of the sensor based on the SiO ₂ -ZrO ₂ film. The output signals of the sensors were processed using a wavelet filter in the MatLab program to remove noise using automatic one-dimensional deletion.