Properties Of SnO2 Thin Films Research Articles

Impact of In-doping and post-annealing on the properties of SnO2 thin films deposited by magnetron sputtering

SnO2 is a transparent semiconductor that has shown versatile applications in various fields. This study investigates the impact of In-incorporation and post-annealing on the structural, optical and electronical properties of SnO2 thin films deposited via RF magnetron sputtering. Three SnO2 target compositions were employed, with one unintentionally doped (UID), one with 1.0 at% In, and the other with 18.2 at% In. UV–vis spectroscopy reveals the presence of band tails in the as-deposited films, which can be significantly suppressed through annealing, particularly in air. Oxygen vacancy-related defect states below the conduction band minimum are believed to be responsible. Further, film thicknesses, refractive indices, and absorption coefficients were estimated from the UV–vis spectra of the films, employing the irritative Swanepoel method. The resistivities of SnO2:In films exhibit parabolic trends with respect to annealing temperature with minima values at 300 °C, while that of UID-SnO2 increases monotonically. P-type conductivity was found in the 300 °C-annealed SnO2:18.2 at% In films both in air and N2, with the N2-annealing leading to higher mobility (162.7 cm2·V−1·s−1) and lower resistivity (0.57 Ω·cm). The Fermi levels of the SnO2:In films are found to locate deep inside the bandgap, which is beneficial to form homojunctions with SnO2 of shallow Fermi levels.

Morphological Characterization of Sb-Doped SnO2 Thin Films Developed by Spray Pyrolysis

In the present work, we have successfully deposited Sb antimony doped tin dioxide (SnO2) thin films with different concentrations (0 at%, 1 at%, 3 at% and 5 at%) from a stannous (II) chloride dihydrate solution (SnCl2.2H2O), by the pyrolysis chemical spray deposition technique on ordinary microscope glass substrates preheated to a fixed temperature of 350 °C. After deposition, the films were annealed at temperatures 400 °C for 4h. The aim of this work is on the one hand to study the morphological properties of pure and doped tin dioxide thin films and to determine the different morphological parameters such as: the roughness Ra, Rq and on the other hand to study the effect of Sb doping on the morphological properties of SnO2 thin films. To achieve this purpose, the thickness of all the films was estimated by profilometer with standard scan type. The morphology of the films was examined by atomic force microscope (AFM) in contact mode at room temperature to visualize the surface of our samples (the structure, size and morphology of crystallites ... etc). The 2D and 3D AFM images confirm the formation of nanostructures on the surface, with shapes and dimensions influenced by the amount of antimony doping. All the samples show a polycrystalline morphology, and the grain size progressively decreases with the increase of the Sb concentration (1% and 3%). On the other hand, for high antimony doping (5% Sb) the grains are larger than those observed at 3% doping. The root mean square (RMS) surface roughness values for samples with Sb concentrations (5%) were found to be 8.334 nm.

Structure and Selected Properties of SnO2 Thin Films.

Magnesium and its alloys are attractive temporary implants due to their biocompatibility and biodegradability. Moreover, Mg has good mechanical and osteoinductive properties. But magnesium and Mg alloys have one significant disadvantage: poor corrosion resistance in a physiological environment. Hence, a deposition of various layers on the surface of Mg alloys seems to be a good idea. The purpose of the article is to analyze the structure and morphology of two MgCa2Zn1 and MgCa2Zn1Gd3 alloys coated by SnO2 ALD (atomic layer deposition) films of various thickness. The studies were performed using scanning electron microscopy (SEM), X-ray fluorescence (XRF), and an X-ray diffractometer. The corrosion activity of the thin films and substrate alloys in a chloride-rich Ringer's solution at 37 °C was also observed. The corrosion tests that include electrochemical, immersion measurements, and electrochemical impedance spectroscopy (EIS) were evaluated. The results indicated that SnO2 had a heterogeneous crystal structure. The surfaces of the thin films were rough with visible pores. The corrosion resistance of SnO2 measured in all corrosion tests was higher for the thicker films. The observations of corrosion products after immersion tests indicated that they were lamellar-shaped and mainly contained Mg, O, Ca, and Cl in a lower concentration.

Mg doping effect on the properties of SnO2 thin films synthesized by dip-coating method

Undoped and Mg doped SnO2 thin films were deposited on glass substrates using dip-coating method for the first time. X-ray diffraction analysis of the films revealed a tetragonal rutile phase. A decrease in crystallite size is observed as the Mg doping increases. The transmittance spectrum exhibits a decrease in transmittance from 87% to 62% as the Mg content is increased. The optical band gap narrows from 3.97 eV to 3.93 eV with the increasing of Mg content. MEB showed an increase of grain sizes with increase in Mg concentration. The RMS roughness increases with Mg doping content. FTIR showd O–Sn–O, Sn–OH, Mg–O, and OH–Mg–OH vibration modes. PL spectra indicated that the incorporation of more Mg2+ into the lattice of SnO2 creates additional oxygen vacancies, leading to an increase in the PL emission intensity in the films. A transition from n-type to p-type conduction was observed at 9 wt% Mg doping.

Effect of Cu-Doping Levels on the Structural and Optical Properties of SnO2 Thin Films Prepared by Chemical Spray Pyrolysis

Effect of Cu-Doping Levels on the Structural and Optical Properties of SnO2 Thin Films Prepared by Chemical Spray Pyrolysis

Modulating the Properties of SnO2 Thin Film by Post-Deposition UV-Ozone Treatment

AbstractTin(IV) oxide (SnO2) is a metal oxide renowned for its excellent optoelectronic properties. With the use of simple post-processing methods, the characteristics of SnO2 may be easily modified. In the current work, SnO2 thin films were prepared using the spray pyrolysis technique and were subjected to post-UV-ozone (UVO) treatment for different durations. Characterization techniques including x-ray diffraction, Raman spectroscopy, scanning electron microscopy, energy-dispersive spectroscopy, UV–visible spectroscopy, and photoluminescence spectroscopy were employed to assess the effects of UVO treatment. It was found that UVO treatment had no significant impact on the film's structural characteristics. However, after exposure to UVO, the bandgap was seen to decrease from 3.04 eV to 2.84 eV. Also, photoluminescence investigations revealed that UVO treatment increased the defects in the films with a decrease in the ratio between band-to-band emission and defect emissions. The results indicate that UVO treatment is an effective strategy for tuning the optical properties of SnO2 thin films by precisely managing the bandgap.

Impact of Ta doping on the optoelectronic and catalytic properties of SnO2 thin films

Impact of Ta doping on the optoelectronic and catalytic properties of SnO2 thin films

A Comparison Study the Effect of Doping by Ga2O3 and CeO2 On the Structural and Optical Properties of SnO2 Thin Films

This research deals with the effect of gallium oxide and cerium oxide as dopants on the structural and optical characteristics of tin oxide. Gallium and cerium oxide doped tin oxide was prepared with different doping concentrations (0, 0.03, 0.05 and 0.07) wt. pure and doped tin oxide thin films were prepared by the pulsed laser deposition technique. X-ray diffraction and UV-Visible spectrophotometer were employed to investigate both oxides doping effects. Results showed that all prepared samples have poly-crystalline structure with a preferred plane of crystal growth along (110), where the crystal size grew from 40.3 nm to 64.5 nm and to 43.5 nm for Ga2O3 and CeO2 doped tin oxide thin films, respectively. Transmittance decreased drastically by increasing the doping ratio of gallium oxide. In contrast, it increased by increasing the doping ratio of cerium oxide. The optical energy gap was found to change in nonsystematic sequence with the increase of Ga2O3 doping concentration, while it decreased monotonically by increasing the CeO2 doping concentration.

Effects of gamma radiation on structural, optical, and electrical properties of SnO2 thin films

Gamma irradiation at specific doses controls the material properties of thin films because of its high-ionization energy and high penetrating power. In the present work, the effects of gamma irradiation (γ-rays) on the structural, morphological, electrical, and optical properties of pulsed laser-deposited SnO2 thin films were examined. These films were exposed to γ-rays for doses of 0, 75, 100, 125, and 200 kGy. X-ray diffraction analysis reveals that the films are polycrystalline with a crystallite size of 49.27 nm and it increases with the gamma doses. While the dislocation density and the microstrain decrease, the band gap reduces from 3.8 eV to 3.4 eV with the increase in doses. Raman spectra show the presence of defects caused by gamma irradiation and the photo luminance spectra demonstrate a decrease in the peak intensities for thin films. The blue emission at 437 nm, is associated with oxygen-related defects produced during the phase formation. The Hall measurements confirm that these films are of n-type semiconductors. The I–V characteristics show a rise in conductivity linearly up to 125 kGy and a reduction at 200 kGy due to oxygen vacancies created at the higher gamma doses. The electrical conductivity of all the films increases as a function of temperature, and gamma doses as evident from the rectification behavior. This study infers that gamma rays can modify the material properties hence these films are useful as an electrode for sensing and radiation detection.

Study The effect of Annealing and Argon Laser Irradiation on the optical properties of SnO2 Thin film

In this research we study the effect of Argon Laser Irradiation and annealing on the some optical properties of SnO2 Thin film . These films were prepared by chemical spray pyrolysis method. The film thickness was 1500 A°. optical properties such as (Reflection, Energy band gab, Absorption coefficient, Refractive index, and extinction coefficient) as a function of photon energy have been studied within the wavelength range (300-900) nm, using (u v-visible) Spectrophotometer, before and after irradiation and annealing. it is found that the optical properties were change .

Effect of Al doping on the Structural properties of SnO2 thin films prepared by (sol-gel) method

Undoped and Al-doped SnO2 thin films have been prepared by sol–gel spin coating process on glass substrate for different doping (0, 2.5 ,5 ,7.5,10)% The starting precursor was used as tin chloride dihydrate (SnCl2.2H2O), ethanol , with and without stabilizer. As annealing in a temperature 500°C for one hours, the results of (X-Ray ) diffraction showed that the films have a Polycrystalline structure and increased intensity when use stabilizer and orientation was (020) with lattice constants (a=4.796, b=5.796, c= 5.193) Å.
 The surface morphology of the (SnO2: Al) thin films have been studied using atomic force microscopy (AFM) which indicated that the grown films showed good crystalline and homogeneous surface. The Root Mean Square (RMS) values and surface roughness of the films increased with increasing doped concentration specify when use stabilizer.

Effect of gadolinium substitution on structural, morphological, and electrical properties of SnO2 thin films

Effect of gadolinium substitution on structural, morphological, and electrical properties of SnO2 thin films

Study of structural and morphological properties of RF-sputtered SnO2 thin films and their effect on gas-sensing phenomenon

Abstract The present work focuses on understanding the impact of varying the thickness of SnO2 thin films on its gas-sensing response. Systematic studies were conducted by X-ray diffraction (XRD) and atomic force microscopy (AFM) on the structural and morphological properties of SnO2 thin films, which were thereafter correlated for a deeper understanding of the sensing phenomenon. The structural and morphological properties of SnO2 thin films were found to be highly dependent on the film thickness. The 90 nm SnO2 thin film exhibits the maximum sensing response to 200 ppm liquefied petroleum gas (LPG). A rough microstructure and the maximum surface-to-volume ratio of the 90 nm SnO2 thin film favors the gas-sensing response. It also possesses the smallest grain size, with the majority of crystallites oriented along the preferred (110) plane. The results suggest the possibility of utilizing the 90 nm SnO2 thin film as a base material, which can be further modified using a catalyst for the efficient detection of LPG gas in the future.

Enhanced infrared transmittance by modulation of electrical and optical properties of Sm-doped SnO2 thin films

Although metal oxides exhibit high electrical conductivity and high transparency in the visible wavelength range, they suffer from low transmittance in the infrared (IR) spectral range. This paper reports the deposition of Sm-doped SnO2 thin films with high IR transparency by modulating the electrical and optical properties. The Sm-doped SnO2 thin films grown by spray pyrolysis showed a directional columnar structure and a change in crystal structure from tetragonal to orthorhombic with increasing Sm doping content. The undoped SnO2 thin film exhibited intrinsic n-type conductivity with a high background charge carrier concentration, which resulted in low IR transmittance of <20%. As the Sm doping content increased, the charge carrier concentration decreased drastically, resulting in an increase in IR transmittance of SnO2 thin films from 18.8 to 85.2%. The Sm element acted a critical role in controlling the electrical and optical properties of SnO2 thin films by acting as a reducing agent and dopant.

Influence of Ru doping on the structural, morphological, optical, electrical and optoelectronic properties of SnO2 thin films

Tin oxide (SnO2) and various concentrations (1, 2, 3 and 4 wt%) of ruthenium (Ru)-doped tin oxide (SnO2:Ru) films were deposited on microscope glass slides using an economical laboratory-made spray pyrolysis method. The influence of Ru doping on the physical properties of SnO2 films was studied using X-ray diffraction (XRD), UV–visible–near-infrared spectroscopy, scanning electron microscopy (SEM), energy dispersive spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, photoluminescence (PL), micro-Raman spectroscopy and Hall measurement analyses. The XRD result corroborates that all the prepared films belong to tetragonal crystal structure with P42/mnm space group and reveals that crystallite size decreases from 29.06 to 22.41 nm. The 3 wt% Ru-doped SnO2 film has a high average optical transmittance (88%) in the range of 400–1100 nm. The calculated optical band gap ranges within 3.50–3.76 eV. The SEM micrographs reveal the morphology changes and grain size decrement as a function of Ru doping. Metal oxide vibration (O–Sn–O) is confirmed using FT-IR and micro-Raman spectral analyses. The PL spectra measured at room temperature exhibit a strong blue emission at 420 nm for all films. All prepared thin films show resistivity of the order of 10−3 Ω cm. The highest figure of merit of 2.627 × 10−4 Ω−1 is obtained for 3 wt% of Ru doping in the wavelength range of 400–1100 nm. The present investigation clearly shows that the structural, optical, morphological, electrical and optoelectronic properties of SnO2 thin films are effectively modified by the Ru dopant. Particularly, the 3 wt% of Ru-doped SnO2 films could be useful for the electron transport layer in solar cells and other optoelectronic applications.

Detection of ammonia gas at room temperature through Sb doped SnO2 thin films: Improvement in sensing performance of SnO2

This paper presents the effects of Sb doping on the gas-sensing properties of SnO2 thin films prepared through a nebulizer-assisted spray pyrolysis technique. An improvement in the inherent characteristics of the transparent conducting oxide after 0 to 5 wt% Sb doping is reported. The deposited films were used to sense the presence of 50 to 250 ppm of ammonia at room temperature. Various analytical techniques were used to analyze the properties of the Sb-doped SnO2 films. X-ray diffraction spectra revealed the tetragonal structure of crystallites, and the maximum crystallite size was observed in the 2-wt%-Sb-doped SnO2 film. The morphological images showed spherical grains in pristine SnO2 films and their transformation to a trigonal shape after Sb doping; particularly, a large grain size was observed at 2 wt% doping. PL studies of the materials revealed that a large number of oxygen vacancies exist in the 2-wt%-Sb-doped SnO2 thin film. The transmittance of the films remained at approximately 75%, and the band gap varied from 3.94 to 4.01 eV as the doping concentration varied from 1 to 5%. A high response of 138% was observed for 250 ppm of ammonia in the case of the 2-wt%-Sb-doped SnO2 film, with a 42 s response time and a 11 s recovery time. Thus, the 2-wt%-Sb-doped SnO2 thin film has suitable characteristics for application as an efficient gas sensor to detect ammonia.

Al3+ doping induced changes of structural, morphology, photoluminescence, optical and electrical properties of SnO2 thin films as alternative TCO for optoelectronic applications

Highly transparent and conductive pure (SnO2) and aluminum doped tin oxide (Al:SnO2) thin films were deposited on glass substrates by the sol-gel spin-coating method. The structural, morphological, optical and electrical properties of the prepared thin films at different doping rates have been studied. X-ray diffraction results revealed that all the films were polycrystalline in nature with a tetragonal rutile structure. SEM images of the analyzed films showed a homogeneous surface morphology, composed of nanocrystalline grains. The EDS results confirmed the presence of Sn and O elements in pure SnO2 and Sn, O, Al in doped SnO2 thin films. The optical results revealed a high transmittance greater than 85% in the visible and near infrared and a band gap varying between 3.82 and 3.89 eV. PL spectra at room temperature showed that the most dominant defects correspond to oxygen vacancies. A low resistivity of order varying between 10−3 and 10−4 Ω cm and a high figure of merits ranging between 10−3 and 10−2 Ω−1 in the visible range were obtained. The best performances were obtained for samples containing 2 at. % Al, which could be used as an alternative TCO layer for future optoelectronic devices.

A Multimodal Sensing Device for Simultaneous Measurement of Dissolved Oxygen and Hydrogen Ions by Monolithic Integration of FET-Based Sensors.

We examined the possibility of measuring dissolved oxygen by using a potentiometric solid-state semiconductor sensor. Thin films of tin (IV) oxide (SnO2) are widely used in oxygen gas sensors. However, their ability to detect dissolved oxygen (DO) in solutions is still unknown. In this paper, we present a method for investigating the dissolved oxygen-sensing properties of SnO2 thin films in solutions by fabricating a SnO2-gate field-effect transistor (FET). A similarly structured hydrogen ion-sensitive silicon nitride (Si3N4)-gate FET was fabricated using the same method. The transfer characteristics and sensitivities were experimentally obtained and compared. The transfer characteristics of the FET show a shift in threshold voltage in response to a decrease in DO concentration. The SnO2-gate FET exhibited a sensitivity of 4 mV/ppm, whereas the Si3N4-gate FET showed no response to DO. Although the SnO2-gate FET responds to pH changes in the solution, this sensitivity issue can be eliminated by using a Si3N4-gate FET, which is capable of selectively sensing hydrogen ions without DO sensitivity. The experimental results indicate the promising properties of SnO2 thin films for multimodal sensing applications.

Effects of Ta, Nb, Ba, and Sb concentration on structural, electrical, and optical properties of SnO2 thin films prepared by metal organic decomposition using spin coating

Ta-, Nb-, Ba-, and Sb-doped SnO2 thin films were prepared by the metal organic decomposition (MOD) method using spin coating. The effects of dopant concentration on the structural, electrical, and optical properties were investigated. The growth of polycrystalline films with the tetragonal rutile structure was confirmed by X-ray diffraction and atomic force microscopy measurements. The resistivity of Ta-, Nb- and Sb-doped SnO2 samples decreased to ∼10−3 Ωcm for dopant concentrations of around 1.5–3.0 at.%. The lowest resistivities were obtained for Ta- and Sb-doped SnO2 samples. On the other hand, no decrease in resistivity was observed for Ba-doped SnO2 samples. The band gap energy of Ta-, Nb-, Ba-, and Sb-doped SnO2 samples appeared to be larger than for those prepared by other methods. It was suggested that the structural deterioration may be related to the increase in the band gap energy for MOD prepared samples in addition to the Burstein-Moss effect.

Bi-doped SnO2 transparent conducting thin films deposited by spray pyrolysis: structural, electrical, optical, and photo-thermoelectric properties

In this research, light and heavy Bi-doped SnO2 thin films were prepared on glass substrates by spray pyrolysis technique. The effect of heavy doped-Bi on the structural, morphological, electrical, photo-thermo-electrical, optical properties of SnO2 thin films has been investigated. The Bi/Sn atomic ratios (x = [Bi/Sn]) were varied from 0 to 0.30 in the spray solution. X-ray diffraction analysis showed the formation of SnO2 tetragonal rutile structure in low doped deposited thin films and amorphous structure for heavy Bi-doped SnO2. Also, the SnO2–Bi2O3 binary thin films were formed for x = [Bi/Sn] = 0.05. Scanning electron microscopy images indicated that the nanostructure of the condensed thin films has a rectangular-particle growth toward particle-spherical growth. The Hall effect measurements have shown n-type conductivity in all deposited thin films. The lowest sheet resistance of 39.3 MΩ/□ and highest carrier concentration of n = 4.53 × 1018 cm−3 was obtained for the thin film deposited with x = 0.10. The maximum of the Seebeck coefficient (S) = 325 μVK−1 and figure of merit (ZT) = 1.85 was obtained for the thin film deposited with x = 0.20. The average transmittance of thin films varied over the range of T = 72–84%. The bandgap values of samples were obtained in the range of Eg = 3.52–3.88 eV for the direct band gap. From the photoconductivity studies, the sample prepared with x = 0.20 exhibited the highest photoconductivity among the SnO2: Bi thin films.