Properties Of Tin Oxide Films Research Articles

Studies on physical properties of tin oxide films

This paper reports the study of some physical properties of thin films of tin oxide, such as the structural properties, surface morphology and optical transmission and reflection. The thin films of tin oxide were deposited by the method of thermal evaporation under vacuum. Transmission electron microscopy (TEM) was used to study the structural properties and the atomic force microscopy (AFM) method was used to study the surface morphology of thin films of tin oxide. The absorption and extinction coefficients of the investigated thin layers were determined from the transmittance and reflectance spectra recorded in the range of wavelengths between 190 and 1100 nm.

The Influence of Lyophobicity and Lyophilicity of Film-Forming Systems on the Properties of Tin Oxide Films

In this work, the effects of lyophobicity and lyophilicity of film-forming systems on the properties of thin nanostructured films was studied. Systematic series of experiments were carried out with lyophilic film-forming systems: SnCl4/EtOH, SnCl4/EtOH/NH4F, SnCl4/EtOH/NH4OH and lyophobic systems: SnO2/EtOH and SnO2/EtOH/NH4F. Film growth mechanisms are determined depending on the type of film-forming system. The surface of the films was studied using a scanning electron microscope and an optical microscope. The spectrophotometric method is used to study the transmission spectra and the extinction coefficient. The surface resistance of the films was determined using the four-probe method. The quality factor and specific conductivity of the films are calculated. It was found that the addition of a fluorinating agent (NH4F) to a film-forming system containing SnO2 in the form of a dispersed phase does not lead to an increase in the specific conductivity of the films. X-ray diffraction analysis proved the incorporation of fluorine ions into the structure of the film obtained from the SnCl4/EtOH/NH4F system by the presence of SnOF2 peaks. In films obtained from SnO2/EtOH/NH4F systems, there are no SnOF2 peaks. In this case, ammonium fluoride crystallizes as a separate phase and decomposes into volatile compounds.

Properties of tin oxide films grown by atomic layer deposition from tin tetraiodide and ozone.

Polycrystalline SnO2 thin films were grown by atomic layer deposition (ALD) on SiO2/Si(100) substrates from SnI4 and O3. Suitable evaporation temperatures for the SnI4 precursor as well as the relationship between growth per cycle and substrate temperature were determined. Crystal growth in the films in the temperature range of 225-600 °C was identified. Spectroscopic analyses revealed low amounts of residual iodine and implied the formation of single-phase oxide in the films grown at temperatures above 300 °C. Appropriateness of the mentioned precursor system to the preparation of SnO2 films was established.

Investigation of the effect of adding a moderate amount of hydrogen on the properties of tin oxide films deposited by DC magnetron sputtering

We investigated the effect of adding small amounts of hydrogen during DC magnetron sputtering of SnO x films followed by annealing in a nitrogen atmosphere at temperatures below the instability of SnO. Hard X-ray photoelectron spectroscopy analysis showed a difference in the initial Sn content in the as-deposited samples, which suggests an increased number of V Sn vacancies. This led to the formation of V Sn -H complexes, resulting in a doubling of the concentration of holes from 5.89 × 1017 cm−3 to 1.38 × 1018 cm−3 and a slight increase in the mobility from 1.17 cm2/(Vs) to 1.45 cm2/(Vs) after annealing. Thermal desorption spectroscopy revealed increased desorption of hydroxyl groups after the addition of hydrogen, indicating that hydrogen presence in the film as OH bonds may be the reason for the undesired increase in SnO2 content and raising of the crystallization point. The average transmittance of the hydrogen-added sample was 10% greater than that of the hydrogen-free sample.

The Effect of Temperature Variations on the Optical Properties of Tin Oxide Film with Doping Aluminum, Fluorine and Indium for Semiconductor Electronic Devices

The manufacture of a thin layer of SnO2: (Al + F + In) was carried out by using the sol-gel spin coating method on a glass substrate with various temperatures (25, 50, 100, 150, and 200 °C).The purpose of this study is to determine the optical properties of thin layers which include transmittance, absorbance, band gap energy and activation energy. The optical properties of the coating were characterized using a UV-Vis spectrophotometer with a wavelength of 200-1100 nm. The results showed that the absorbance value increased with increasing temperature at a wavelength of 300 nm. The absorbance values ​​obtained for temperature variations were in the percentages of 95: 5% and 75: 25%, respectively 3.46-4.50 and 3.96-5.76. The transmittance value obtained increased, namely 73.00-86.30% and 74.20-99.30%. In addition, the energy band gap decreased from 3.60-3.41 eV and 3.57-3.31 eV for direct allowed, while 3.69-3.58 eV and 3.65-3.54 eV for indirect allowed. Activation energy decreased from 2.00-1.18 eV and 1.60-1.12 eV. In general, the absorbance and transmittance values ​​increase with increasing ripening temperature and the addition of doping aluminum, fluorine, and indium, while the bandgap energy and activation energy values ​​obtained decrease with increasing ripening temperature and increasing the doping percentage of aluminum, fluorine, and indium. The decrease in the value of the bandgap energy and the activation energy can make it easier for electrons to move from the valence band to the conduction band so that the material is slightly conductive and acts as a semiconductor.

Effect of Annealing Temperature on Properties of Tin Oxide Films Prepared by Electrostatic Deposition Technique

Abstract In this work, tin oxide films were prepared by electrostatic spray deposition technique. The effect of post annealing temperature on properties of prepare film was performed. The structural, surface morphology and optical properties of tin oxide films were characterized by X-ray diffraction, field-emission scanning electron microscope, and UV-Visible spectrophotometer. The crystalline size is found to increase with increase the annealing temperature. Moreover, the effect of annealing temperature on physical properties of tin oxide films has been performed

The effect of three-minute exposure of oxygen plasma on the properties of tin oxide films

Research devoted to the effect of three-minute exposure of oxygen plasma on the properties of tin oxide films investigation. The films were obtained by sol-gel method from five-water tin tetrachloride solution. The concentration of tin ions in the SnCl4/EtOH film-forming system was 0.14 mol/l. The solution system was deposed on the glass substrate by carring out a modified dipping method. Plasma treatment was performed at a pressure of 6.5 Pa and a power of about 20 Watts. The frequency of the oscillations produced by the generator was 27.12 ± 0.6 % MHz as well. The temperature of the samples during processing did not exceed 100 ºC. As a result of the formation of tin oxide (II), the film transmittance decreased after treatment with oxygen plasma. The width of the electric forbidden zone of the obtained samples was calculated, which was 3.95 eV for glass and 3.79 eV for film. The resistance of the films was determined by 10 measurements on different parts of the samples. The film without processing has a resistance of about 4255 ± 1158 kΩ, after processing, the resistance decreased by 25 times and amounted to 167 ± 26 kΩ. A decrease in resistance indicates an increase in the concentration of charge carriers in the sample. The resulting SnO is a semiconductor that lowers the transmittance of the studied films and contributes to reducing their resistance. X-ray structural analysis of the samples was also performed. After processing in oxygen plasma, the intensity of reflection from the (110) plane have increased. It should be noted that the number of planes with (101) indexes has decreased. The study of the sample surface showed the destructive nature of three-minute exposure by oxygen plasma.

Morphology, Structure, and Optical Properties of SnO (x) Films

The paper presents the morphological, structural, and optical properties of nanostructured SnO (x) films obtained by molecular beam epitaxy using deposition of tin in an oxygen flux on an oxidized silicon substrate as a function of the annealing temperature of the synthesized structure. The effect of annealing temperature on the structural and phase state of the films is established. The orthorhombic phase of SnO2 was observed after annealing in air at 500°C. An increase in the annealing temperature up to 800°C leads to the appearance of small fraction of the tetragonal phase of SnO2. The effect of the crystal structure on the optical properties of tin oxide films is shown. Ellipsometry revealed a sharp change in the optical constants of the film near the annealing temperature of 500°C. The observed wide absorption band in the range 1.9–3.4 eV is apparently associated with small (approximately 1%) amount of unoxidized metal Sn clusters. Photoluminescence in a wide range of 450–850 nm with a maximum at ~600 nm is observed. An increase in the annealing temperature from 500 to 800°С leads to an increase in the PL intensity by almost a factor of 6.

Impact of thermal oxygen annealing on the properties of tin oxide films and characteristics of p-type thin-film transistors

In this work, we study the properties of tin oxide films, which were annealed in oxygen ambient for various periods. The as-deposited tin oxides are tin-dominant and, from the Hall measurements, they are of the n-type with high electron concentrations (>1019 cm−3) and would change to the p-type when the oxygen annealing is sufficiently long. We have also found that changes in the structure and crystallinity of the channel layer can be clearly observed by X-ray diffraction analysis and optical microscopy. On the basis of the observations, a physical scheme is proposed to describe the evolution of the electrical performance of oxygen-annealed devices. A hole mobility of 3.24 cm2 V−1 s−1, a subthreshold swing of 0.43 V/dec, a threshold voltage of 1.4 V, and an on/off current ratio larger than 103 are obtained as the channel is transformed into SnO.

Electrical and optical properties of Co2+:SnO2 thin films deposited by spray pyrolysis technique

In this work, tin oxide (SnO2) and cobalt doped tin oxide (Co:SnO2) thin films are deposited by spray pyrolysis technique and the influence of doping concentration on the structural, morphological, electrical and optical properties of tin oxide films is analyzed and reported. X-ray diffraction pattern shows that the SnO2 and Co:SnO2 films are polycrystalline in nature and exhibit tetragonal crystal system. Co doping shifts the preferential growth orientation of SnO2 to (200) direction. Scanning electron microscopic studies show that the surface morphology of tin oxide films was effectively modified by various Co concentrations. X-ray photoelectron spectra of 5 at.% Co:SnO2 thin film reveal the presence of tin, oxygen, and cobalt. Carrier concentration and mobility of the SnO2 film decreases with increasing Co concentration and 0.5 at.% Co:SnO2 film acquires a mobility of 74 cm2/V s. The average optical transmittance of SnO2 thin film in the range of 500–800 nm increases due to Co doping.

LPG sensing characteristics of electrospray deposited SnO2 nanoparticles

In this study, SnO2 films were fabricated on conductive substrate such as aluminum and platinum coated alumina using electro-spray deposition (ESD) method for gas sensor applications. Solution flow rate, coating time, substrate–nozzle distance and solid/alcohol ratio were studied to optimize SnO2 film structure. The morphology of the deposited films was characterized by stereo and scanning electron microscopy (SEM). The gas sensing properties of tin oxide films were investigated using liquid petroleum gas (LPG) for various lower explosive limit (LEL). The results obtained from microscopic analyses show that optimum SnO2 films were evaluated at flow rate of 0.05ml/min, at distance of 6cm, for 10min deposition time, for 20gSnO2/Lethanol ratio and at 7kV DC electric field. By the results obtained from the gas sensing behavior, the sensitivity of the films was increased with operating temperature. The films showed better sensitivity for 20 LEL LPG concentration at 450°C operating temperature.

A sharp and visible range plasmonic in heavily doped metal oxide films

As alternatives to conventional metals, metal oxide semiconductors offer many advantages in the field of plasmonic applications. Herein, the influence of antimony doping on the plasmon resonance properties of tin oxide films prepared by spray pyrolysis has been investigated. The colour of heavily doped antimony tin oxide films was tuned from colourless (transparent) to dark bluish. The crystallinity and morphology of these films were studied by x-ray diffraction and scanning electron microscopy. X-ray diffraction reveals that these films have purely cassetirite structure and no secondary phases of tin and antimony oxides are present. The surface morphology shows films have grainy structure which decreases with increase in antimony content. The Hall effect and electrical conductivity measurements show that the majority carriers are electrons and conductivity decreases by three orders of magnitude with increase in antimony content up to 50 wt%. The optical absorption shows that with increase in doping the plasmon peak becomes sharp and shifts to the visible region. Such plasmonic features are rarely reported on such materials. These results are analysed in terms of classical theory of surface plasmon resonance. The better plasmonic features, low cost, ease of synthesis and good chemical stability make these materials potential candidates for plasmonic applications.

Effects of Substrate Temperature on Structural Properties of Tin Oxide Films Produced by Plasma Oxidation after Thermal Evaporation

In this study, tin lm was thermally evaporated onto a stainless steel substrate in an argon atmosphere. The tin lms were then subjected to a DC plasma oxidation process using an oxygen/argon gas mixture. Three di erent substrate temperatures (100 ◦C, 150 ◦C, and 200 ◦C) and three di erent oxygen partial pressures (12.5%, 25%, and 50%) were used to investigate the physical and microstructural properties of the lms. The surface properties were studied by scanning electron microscopy, X-ray di raction, atomic force microscopy and a four-point probe electrical resistivity measurement. The grain size and texture coe cient of the tin oxide lms were calculated. Both SnO and SnO2 lms with grain sizes of 13 43 nm were produced, depending on the oxygen partial pressure. SnO lms have owerand ake-like nanostructures, and SnO2 lms have grape-like structures with nanograins. The resistivity values for the SnO2 phase were found to be as low as 10 −5 Ω cm and were observed to decrease with increasing substrate temperature.

Influence of the Thickness and Substrate Temperature on the Structure and Properties of Tin Oxide Films by RF Magnetron Sputtering

Tin oxide films were successfully prepared on glass substrates by radio frequence (RF) magnetron sputtering with a ceramic target under different substrate temperatures. To investigate the influence of substrate temperature on the prepared films, the thickness of as-deposited films was fixed at 240–260 nm. Tin oxide films were annealed at 450°C in air ambient for 60 min. Structure, optical and electrical properties of as-deposited and annealed films have been studied as a function of film thickness and substrate temperature. The crystallinity of the films is strongly dependent on the film thickness and growth temperature, which in turn has a great effect on the optical and electrical properties of the films. The average transmittance in ultraviolet region, E g and resistivity of the films are obviously improved after annealing. The stability of the CdS/CdTe solar cells is improved by introducing the high resistance transparent film (HRT).

Structural, morphological, electrical and optical studies of Cr doped SnO2 thin films deposited by the spray pyrolysis technique

Tin oxide (SnO2) and chromium (Cr) doped tin oxide (Cr:SnO2) thin films were deposited on the preheated glass substrates at 673K by spray pyrolysis. Concentration of Cr was varied in the solution by adding chromium (III) chloride hexahydrate from 0 to 3at%. The effect of Cr doping on the structural, electrical and optical properties of tin oxide films is reported. X-ray diffraction pattern confirms the tetragonal crystal structure for undoped and Cr doped tin oxide films. Scanning electron microscopic photographs show the modification of surface morphology of tin oxide film due to varying concentration of Cr. X-ray photoelectron spectra of Cr:SnO2 (3at%) thin film revealed the presence of carbon, tin, oxygen, and chromium. Carrier concentration and mobility of the SnO2 films decrease with increasing concentration of Cr and 0.5at% Cr doped tin oxide film acquires a mobility of 70cm2/Vs. Average optical transmittance in the 550–850nm range varies from 38% to 47% with varying Cr concentration in the solution.

The combined effects of molar concentration of the precursor solution and fluorine doping on the structural and electrical properties of tin oxide films

Undoped and fluorine doped tin oxide (FTO) films have been fabricated by employing a simplified and inexpensive spray technique using perfume atomizer at comparatively lesser substrate temperature (320 °C). The combined effects of molar concentration of the precursor solution and fluorine doping on the structural and electrical properties of tin oxide films have been reported. The X-ray diffraction studies of undoped films revealed that the interstitial incorporation of Sn atoms can be controlled by employing this simple spray pattern and process conditions. The electrical studies showed that, in governing the variation in sheet resistance, the role of substitutional incorporation of F− ions is predominant over the oxygen vacancies in the case of FTO films deposited from solutions having lower precursor concentration, whereas in the case of higher concentrations the role of oxygen vacancies is predominant. The quantitative results of energy dispersive X-ray analysis (EDAX) and the variations in the Fourier transform infrared (FTIR) peaks are presented as strong evidences for the above observations.

Properties of Tin Oxide Films Deposited by Sol Gel Dip Coating

not Available.

ChemInform Abstract: Effects of Surface Pretreatments of a Glass Substrate on the Properties of Tin Oxide Film Prepared by Plasma-Assisted Chemical Vapor Deposition (PCVD).

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Annealing Effect on Structural and Optical Properties of SnO2 Thin Films

Thin solid films of SnO2 were deposited by chemical vapor deposition (CVD) method on glass substrate at 450C and 2.5L/min.air flow rate. Deposited films were annealed at different temperature (200,300,400,500) C in air for 60 minutes. Structural properties have been studied for annealed and unannealed films. It was found that the films have polycrystalline structure with grain diameter(190-230)A depend on annealing temperature. And the crystal structure is tetragonal with lattice constants (a=b=4.782 ,c=3.233)A. Optical properties also studied for annealed and unannealed films using UV-visible spectroscopy. The transmission spectra showed higher transparency over the visible wave length region with maximum value (85-95)% depend on annealing temperature. Absorption edge energy is increased by annealing temperature from (3.93 to 4.1)eV while Optical energy gap is not affected by annealing and it is found to be (4.17)eV. Annealing Effect on Structural.... 100 Introduction Transparent, electrically conductive films have been prepared from a wide variety of materials. These include semiconducting oxides of tin, indium, zinc and cadmium; and metals such as silver, gold and titanium nitride .They have been used for many years as electrodes or resistive elements and applied to semiconductor devices as transparent gates on charge injection devices and charge coupled devices and as transparent barrier layers on solar cells[1]. The materials mostly used for such applications are tin oxide (SnO2), antimony-doped tin oxide and tindoped indium oxide. These films have been deposited by chemical vapour deposition, sputtering, evaporation and spraying [2]. Tin oxide films is the most used material because of its cheap raw material and highly existing in nature. It is characterized by a wide band gap and high electrical conductivity through the existing of O2 vacancies and interestial tin atoms in the crystal structure of the films and that is depend on method of deposition. Also it is a good transparent antireflecting material. Temperature stability and reproducibility of the film properties are important for device reliability. The films are exposed to heat during the preparation and operation of the device. This may cause structural changes which tend to either influence or degradation in most of the physical properties of the films. The effects of annealing are complex because of the variety of phenomenon that may observe. Many studies have been done on different transparent conducting oxides to find the effect of annealing on certain property of the films such as the refractive index (n), extinction index (k) and energy gap (Eg) for ZnO-SnO2 [3], resistivity and factor of merit for antimony-doped tin oxide[4], grain size, porosity and conductivity of tin-doped indium oxide[5] and many others [6,7,8,9]. In this study structural and optical properties of tin oxide films prepared by chemical vapour deposition are described. Also, the effect of annealing at different temperature in air on structural and optical properties of SnO2 thin films are studied including: grain size, lattice constant, transmission, optical energy gap and absorption edge. Experimental Detail The SnO2 thin films were prepared by CVD technique. Although this technique is well known and used by many workers[10], it still need some modification. We have modified and built this system in physics department, Education college, Mosul university, using the stannous chloride oxidation principle. The diagram of the experimental set-up used for SnO2 deposition is shown in Figure (1). Material used was SnCl2.2H2O (purity 99.99% supplied by Fluka Company). Films were Sanaa M. Al -Delaimy & Rajaa Abdulah Basheer 101 deposited on glass type (Gloim 1003/Italy) at 450°C substrate temperature and 2.5 L/min. gas flow rate. Fig.(1)Schematic Diagram of CVD System for SnO2 Films Deposition When the desired deposition factors were attained and stabilized the tin chloride was melted (melting point 247°C) using coil heater (350°C). The tin chloride vapour was driven through the reactor by maintaining an air flow. Air carries the SnCl2 vapour to form SnO2 film deposited on the hot substrate and the reaction takes place as follows: SnCl2 + O2  SnO2 + Cl2 After finishing the deposition the substrates were brought to room temperature inside the reactor. The deposition systems as well as the method have been described briefly in reference [11]. Some of the films were annealed in air by controllable electric oven type (Heraeus) at temperature (200,300,400,500)°C for 60 minutes, while the others were left without annealing. Structural properties were studied for annealed and unannealed films by X-ray diffraction (XRD) using a Philips X-ray diffractometer model (PW 1130). Source of radiation was Cu K (=1.5405 A°) and the scanning range of 2 was restricted to range (10-60)°. Perpendicular distance between adjacent crystal layers(dhkl) for each grain, Lattice constants (a=b, c) and grain diameter (D) of SnO2 film were calculated using the XRD pattern data and the following equations [12] : 2d hkl sin = n (1) 1 h k l ــ = ــ + ــ + ــ (2)

The Influence of the Sputtering Power on the Structural and Electrochemical Properties of Tin Oxide Films

The Influence of the Sputtering Power on the Structural and Electrochemical Properties of Tin Oxide Films