scholarly journals Sensitivity to Ethanol Vapour of Thin Films SnO2 Doped with Fluorine

2019 ◽  
pp. 13 ◽  
Author(s):  
E.A. Grushevskaya ◽  
S.A. Ibraimova ◽  
E.A. Dmitriyeva ◽  
I.A. Lebedev ◽  
K.A. Mit’ ◽  
...  
Keyword(s):  
Thin Films ◽  
Surface Resistance ◽  
Tin Dioxide ◽  
Ammonium Hydroxide ◽  
Ammonium Fluoride ◽  
Charge Carriers ◽  
Ph Indicator ◽  
Ethanol Vapour ◽  
Film Forming ◽  
Fluorine Ions

Tin dioxide thin films were obtained by centrifuging. Annealing of samples was carried out in a muffle furnace at a temperature of 400 °C for 15 min, 3, 6 and 12 h. The surface resistance of the films was measured by four-force method. The sensitivity to ethanol vapour was determined by experimental setup that allows measurements in the range from room temperature to 300 °C. There is a change in the acidity of the solution with the addition of ammonium fluoride. To take into consideration this change in acidity, three batches of solutions were prepared: one example without additives, another one ‒ with the addition of ammonium fluoride and the last one ‒ with the addition of ammonium hydroxide. Films synthesized from a film-forming solution containing NH4F have less resistance than films obtained from solutions that do not contain ammonium fluoride. This confirms the presence of fluorine ions in the films as additional sources of free charge carriers. It is found that the pH-indicator of the film-forming solution does not affect the surface resistance of the synthesized SnO2 films. Annealing of fluoride doped films leads to an increase in surface resistance by two orders of magnitude, which is associated with the removal of fluorine from the films and the formation of a large number of defects. Further annealing leads to a decrease in surface resistance, which seems to be associated with a decrease in defects. It is shown that the change in the hydrogen index of the film-forming solution leads to the formation of films with a thermally stable sensitivity to ethanol vapour.

scholarly journals Influence of Plasma Treatment on Physical Properties of Thin SnO2 Films Obtained from SnCl4 Solutions with Additions of NH4F and NH4OH

2019 ◽  
pp. 57 ◽  
Author(s):  
D.M. Mukhamedshina ◽  
A.I. Fedosimova ◽  
E.A. Dmitriyeva ◽  
I.A. Lebedev ◽  
E.A. Grushevskaya ◽  
...  
Keyword(s):  
Surface Resistance ◽  
Oxygen Vacancies ◽  
Oxygen Plasma ◽  
Tin Dioxide ◽  
Hydrogen Plasma ◽  
Ammonium Hydroxide ◽  
Film Material ◽  
Wave Region ◽  
Interaction Efficiency ◽  
Effect Of Oxygen

This paper considers the effect of oxygen and hydrogen plasma on SnO2 films synthesized from solutions of tin tetrachloride containing NH4F and NH4OH additives. It was found that the treatment of samples with oxygen plasma for 5 min led to a decrease in transparency by 1.11 and 1.17 times. On the transmission spectra, a decrease in the transmittance at a wavelength of 450 nm to 38.1% (1.24 times) in samples obtained from solutions with the addition of NH4F and up to 29.9% (1.53 times) in samples obtained from solutions with the addition of NH4OH is observed. The formation of tin oxide (II) under the influence of the reducing properties of hydrogen plasma is assumed. At the same time, the formation of metal tin from tin dioxide is not observed here. Due to the decreasing of transmission coefficient in the long-wave region of the spectrum. There is an increase in surface resistance after treatment with oxygen plasma, due to filling oxygen vacancies. Treatment of hydrogen plasma films leads to a decrease in surface resistance. Perhaps due to the increase in oxygen vacancies under the influence of hydrogen plasma. Within five minutes, the oxygen and hydrogen plasma had a more active effect on the films obtained from the solution with the addition of ammonium hydroxide, which is associated with a higher porosity of the sample. Consequently, irrespective of the time of plasma exposure with increasing the surface of contact between ionized gases and the film material, the interaction efficiency will increase.

Effect of aging heat time and annealing temperature on the properties of nanocrystalline tin dioxide thin films

2017 ◽  
Vol 31 (12) ◽  
pp. 1750114
Author(s):  
Imad H. Kadhim ◽  
H. Abu Hassan
Keyword(s):  
Thin Films ◽  
Tin Dioxide ◽  
Sol Gel ◽  
Stable Solution ◽  
Solution Viscosity ◽  
Pure Ethanol ◽  
Rutile Structure ◽  
Heat Time ◽  
Chloride Dihydrate ◽  
P Type

Nanocrystalline tin dioxide (SnO2) thin films have been successfully prepared by sol–gel spin-coating technique on p-type Si (100) substrates. A stable solution was prepared by mixing tin(II) chloride dihydrate, pure ethanol, and glycerin. Temperature affects the properties of SnO2 thin films, particularly the crystallite size where the crystallization of SnO2 with tetragonal rutile structure is achieved when thin films that prepared under different aging heat times are annealed at 400[Formula: see text]C. By increasing aging heat time in the presence of annealing temperatures the FESEM images indicated that the thickness of the fabricated film was directly proportional to solution viscosity, increasing from approximately 380 nm to 744 nm, as well as the crystallization of the thin films improved and reduced defects.

ITO Thin Films on Silicon Buffer by Sol Gel Method

2006 ◽  
Vol 514-516 ◽  
pp. 1155-1160 ◽  
Author(s):  
Talaat Moussa Hammad
Keyword(s):  
Thin Films ◽  
Indium Tin Oxide ◽  
Optical Transmission ◽  
Sol Gel ◽  
Precursor Solution ◽  
Charge Carriers ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ito Thin Films ◽  
Uv Visible

Sol gel indium tin oxide thin films (In: Sn = 90:10) were prepared by the sol-gel dipcoating process on silicon buffer substrate. The precursor solution was prepared by mixing SnCl2.2H2O and InCl3 dissolved in ethanol and acetic acid. The crystalline structure and grain orientation of ITO films were determined by X-ray diffraction. The surface morphology of the films was characterized by scanning electron microscope (SEM). Optical transmission and reflectance spectra of the films were analyzed by using a UV-visible spectrophotometer. The transport properties of majority charge carriers for these films were studied by Hall measurement. ITO thin film with electrical resistivity of 7.6 ×10-3 3.cm, Hall mobility of approximately 2 cm2(Vs)-1 and free carrier concentration of approximately 4.2 ×1020 cm-3 are obtained for films 100 nm thick films. The I-V curve measurement showed typical I-V characteristic behavior of sol gel ITO thin films.

Hydroxylated secondary dopants for surface resistance enhancement in transparent poly(3,4-ethylenedioxythiophene)–poly(styrenesulfonate) thin films

2004 ◽  
Vol 142 (1-3) ◽  
pp. 187-193 ◽  
Author(s):  
Brett D Martin ◽  
Nikolay Nikolov ◽  
Steven K Pollack ◽  
Alexey Saprigin ◽  
R Shashidhar ◽  
...  
Keyword(s):  
Thin Films ◽  
Surface Resistance

scholarly journals Crystal Structure, Lattice Strain, Morphology, and Electrical Properties of SnO2 Nanoparticles Induced by Low Calcination Temperature

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Panya Khaenamkaew ◽  
Dhonluck Manop ◽  
Chaileok Tanghengjaroen ◽  
Worasit Palakawong Na Ayuthaya
Keyword(s):  
Thin Films ◽  
Electrical Properties ◽  
Calcination Temperature ◽  
Tin Dioxide ◽  
Lattice Strain ◽  
Dielectric Constants ◽  
Precipitation Method ◽  
Calcination Temperatures ◽  
Sensing Applications ◽  
Crystallite Sizes

The electrical properties of tin dioxide (SnO2) nanoparticles induced by low calcination temperature were systematically investigated for gas sensing applications. The precipitation method was used to prepare SnO2 powders, while the sol-gel method was adopted to prepare SnO2 thin films at different calcination temperatures. The characterization was done by X-ray diffraction, scanning electron microscopy (SEM), and atomic force microscopy (AFM). The samples were perfectly matched with the rutile tetragonal structure. The average crystallite sizes of SnO2 powders were 45 ± 2, 50 ± 2, 62 ± 2, and 65 ± 2 nm at calcination temperatures of 300, 350, 400, and 450°C, respectively. SEM images and AFM topographies showed an increase in particle size and roughness with the rise in calcination temperature. The dielectric constant decreased with the increase in the frequency of the applied signals but increased on increasing calcination temperature. By using the UV-Vis spectrum, the direct energy bandgaps of SnO2 thin films were found as 4.85, 4.80, 4.75, and 4.10 eV for 300, 350, 400, and 450°C, respectively. Low calcination temperature as 300°C allows smaller crystallite sizes and lower dielectric constants but increases the surface roughness of SnO2, while lattice strain remains independent. Thus, low calcination temperatures of SnO2 are promising for electronic devices like gas sensors.

scholarly journals Study of properties of electrical conductivity of Tin dioxide thin films treated with Xenon impulse radiation used as Gas sensors

2009 ◽  
Vol 6 (4) ◽  
pp. 693-697
Author(s):  
Baghdad Science Journal
Keyword(s):  
Thin Films ◽  
Electrical Conductivity ◽  
Short Duration ◽  
Gas Sensors ◽  
Tin Dioxide ◽  
Experimental Result ◽  
Gas Sensitivity ◽  
Gas Concentration ◽  
Similar Character

During of Experimental result of this work , we found that the change of electrical conductivity proprieties of tin dioxide with the change of gas concentration at temperatures 260oC and 360oC after treatment by photons rays have similar character after treatment isothermally. We found that intensive short duration impulse annealing during the fractions of a second leads to crystallization of the films and to the high values of its gas sensitivity.

scholarly journals Edge Absorption of thin Films –Ga2O3

2015 ◽  
Vol 16 (2) ◽  
pp. 302-306
Author(s):  
O.M. Bordun ◽  
B.O. Bordun ◽  
V.B. Lushchanets ◽  
I.Yo. Kukharskyy
Keyword(s):  
Thin Films ◽  
Heat Treatment ◽  
Absorption Edge ◽  
Optical Band Gap ◽  
Fundamental Absorption Edge ◽  
Hydrogen Atmosphere ◽  
Argon Atmosphere ◽  
Charge Carriers ◽  
Free Charge ◽  
Moss Effect

Fundamental absorption edge of b–Ga2O3 thin films, obtained by radio-frequency ion-plasmous sputtering, was investigated, using the method of optical spectroscopy. It was ascertained that the optical band gap Eg increases from 4.60 to 4.65 eV after the heat treatment films in argon atmosphere and to 5.20 eV after the reduction of annealed films in a hydrogen atmosphere. Consolidated effective mass of free charge carriers in b–Ga2O3 films after annealing and after reduction in hydrogen was estimated. It was found that the concentration of charge carriers after heat treatment in argon atmosphere is 7.30´1017 cm–3 and after reduction in hydrogen, is 2.62´1019 cm–3, which is typical for degenerated semiconductors. It was shown that the shift of fundamental absorption edge in thin films b–Ga2O3 after reduction in hydrogen is caused by Burstein-Moss effect.

scholarly journals Obtaining the conductive SnO2 films by chemical bath deposition method

2019 ◽  
Vol 60 (11) ◽  
pp. 1-10
Author(s):  
Vladislav I. Rogozin ◽  
◽  
Vyacheslav F. Markov ◽  
Larisa N. Maskaeva ◽  
Anastasia E. Krasovskaya ◽  
...  
Keyword(s):  
Tin Dioxide ◽  
Solid Phase ◽  
Average Particle Size ◽  
Ammonium Fluoride ◽  
Contact Layer ◽  
Average Particle ◽  
Solution Ph ◽  
Before And After ◽  
Initial Salt ◽  
Conductive Properties

Thanks to such unique properties as transparency and conductivity tin dioxide often utilize as transparent contact layer to produce displays, solar cells, and sensor devices. Hydrochemical method of deposition SnO2 films is a perspective due to its simplicity, and economical efficiency. The ionic equilibria analysis was carried out and the boundary conditions of Sn(OH)2 solid phase formation in the «Sn2+ – H2O – OH‾» system calculated. It was established, that tin(II) hydroxide may be obtain in the range 2 < pH < 12. Preliminary results allow to determinate an optimal mixture sourness interval 1 < pH < 5. Revealed, that the thickness of the Sn(OH)2 films strongly depends on the solution pH. Maximum value of 488 nm reached at pH = 8. Conductive SnO2 layers were obtained on a glass and sitall substrates with simultaneously presence of antimony chloride and ammonium fluoride followed by annealing in air. The thickness vs temperature and thickness vs tin initial salt concentration dependences were installed. The uniform tin hydroxide layers with a thickness of ~74 nm may be synthesized under pH = 2 conditions. By the electron microscopy method the average particle size was established changing from 200 to 400 nm for as-synthesized films, to ~20 nm for annealed which indicates the nanostructure nature of the films. The morphology, elemental composition and conductive properties of deposited films were investigated before and after heating stage. Studying the annealing temperature influence at the film resistance were identified a three temperature ranges within which the films sharply differ in their conductive properties, which is associated with phase and structural transformations in them. Shown, that the most conductive SnO2 films with the omic resistance 3-5 kOm/sm were obtained at the temperature range 620-870 K.

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