Effect of annealing temperature of titanium dioxide thin films on structural and electrical properties (original) (raw)
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Journal of Scientific Research, 2016
The effect of annealing temperatures on the surface morphology and optical properties of titanium dioxide (TiO 2 ) thin films deposited by spin coating on Silicon substrate was studied. The TiO 2 thin films deposited onto silicon substrates were annealed at different temperatures. The structural and optical properties were studied using scanning electron microscopy (SEM), X-ray diffraction technique (XRD) and optical ellipsometer. The results indicated that the structural properties of the TiO 2 thin films were changed with the increase in annealing temperature. The SEM investigation showed that as annealing temperature was increased, the grain and pores size were increased. The XRD patterns of the studied samples showed that rutile phase were found in a sample annealed at high temperature. The ellipsometry investigation shows that the refractive index increased while energy band gap decreased with the annealing temperature. The results showed that surface porosity, optical properti...
AIP Conference Proceedings, 2010
Recently, ceramic metals (cermets) have been widely investigated for use as embedded resistor materials. In this study, SiO-Pt nano-composite cermets were developed to control the resitivity and temperature coefficients of resistance (TCR) of embedded thin film resistors. The SiO-Pt nanocomposite was prepared by the co-sputtering of a SiO x target and Pt chips onto glass. The experiments were conducted Pt concentrations in order to find the optimum conditions to achieve a high resistivity and low TCR. The electrical properties of the sputtered SiO-Pt thin films were investigated by probe station and their crystal structures were observed by X-Ray Diffraction (XRD) and X-ray Photoelectron Spectroscopy (XPS). The surface morphology was observed by field emission scanning electron microscopy (FE-SEM) and high resolution transmission electron microscopy (HR-TEM). It was found that the Pt particles with a size of 3∼5 nm were uniformly dispersed in the SiO matrix. A stable resistivity value of 26000∼57000 •cm and TCR value of −197∼−322 ppm/K were obtained at 3.5∼3.7 at.% Pt.
Vacuum, 2015
In this study the influence of deposition temperature and a post-deposition annealing process on the optical, electrical, mechanical, and tribological properties of titanium oxide thin films was investigated. Based on high-resolution XPS, it was observed that the films became more metallic as the deposition temperature was raised from 15 to 450°C. Moreover, the mechanical and tribological properties of the film deposited at 450°C were at least 50% greater than for the film deposited at 15°C. After annealing at 450°C for 30 mins in air, the films all became transparent and insulating. However, the annealing process had mixed effects on the mechanical and tribological properties such that the 15 and 250°C films softened, but the 450°C film hardened. This mixed trend is attributed to the different as-deposited film stoichiometries. The results show that the coupled effects of deposition temperature and post-deposition annealing are quite complex and that the mechanical properties of TiO 2 thin films can be controlled independently of their optical and electrical properties. This is important because TiO 2 coatings are often used as the outer-most layers in optical devices.
International Journal of Integrated Engineering, 2011
Fabrication of titanium dioxide (TiO 2) thin film on microscope glass using sol-gel method has been studied intensively. The starting materials were titanium (IV) butoxide, ethanol, acetic acid, triton x-100, hydrochloric acid and deionized water. The materials were mixed together to form the sols. Then, the heat and ageing treatment was applied to form stable sols. The sols were then spin coated on the glass substrate to form the homogenous and transparent TiO 2 thin film. The TiO 2 thin film was coated at several layers using specific conditions. To evaluate the performance of thin film, the crystallinity of the thin film was determined by using the x-ray diffractometer (XRD). The change on the surface morphology was observed using atomic force microscope (AFM). The electrical property of the thin film was determined by doing the current-voltage (I-V) analysis on the thin film. It has been successfully shown that the anatase crystalline phase was observed when the TiO 2 thin film was heated at 500°C. The roughness and the crystalline phase of TiO 2 thin film changed drastically with the growth conditions. Finally, the effect of film preparation to the film resistivity also showed a critical aspect where we should take into account during the preparation of TiO 2 thin film.
2016
Titanium dioxide (TiO2) thin films were deposited on silicon substrates by using a sol-gel dip coating technique. In order to study the influences of the deposition layer on the properties of TiO2 films, the number of layer was varied. Then, the TiO2 films were analyzed by X-ray diffraction (XRD), field emission scanning electron microscope (FESEM) and fourpoint probe. Generally, all films are uniform without the presence of any grain or grain boundary. The TiO2 films were confirmed by energy-dispersive X-ray spectroscopy (EDS) which indicates the presence of titanium (Ti) and Oxygen (O). It was found that, the thickness and crystallite size of the films increases as the deposition layers increased. On the contrary, the resistivity of the TiO2 films decreases in the range of 5.80 x 10 2 Ω.cm and 1.45 x 10 Ω.cm as the deposition layer increased. Therefore, it has been determined that the properties of TiO2 films were strongly correlated with the thickness of the films.
Effect of thermal annealing on the structure and microstructure of TiO 2 thin films
Indian Journal of …, 2009
Nanostructured TiO 2 thin films have been prepared through chemical route using sol-gel and spin coating techniques. The deposited films were annealed in the temperature range 400-1000°C for 1 h. The structure and microstructure of the annealed films were characterized by GAXRD, micro-Raman spectroscopy and AFM. The as-deposited TiO 2 thin films are found to be amorphous. Micro-Raman and GAXRD results confirm the presence of the anatase phase and absence of the rutile phase for films annealed up to 700°C. The diffraction pattern of the film annealed at 800 to 1000°C contains peaks of both anatase and rutile reflections. The intensity of all peaks in micro-Raman and GAXRD patterns increased and their width (FWHM) decreased with increasing annealing temperature, demonstrating the improvement in the crystallinity of the annealed films. Phase transformation at higher annealing temperature involves a competition among three events such as : grain growth of anatase phase, conversion of anatase to rutile and grain growth of rutile phase. AFM image of the asdeposited films and annealed films indicated exponential grain growth at higher temperature.
Applied Nanoscience, 2015
The conducting nature of nanocrystalline TiO 2 thin film coated on glass and silicon (Si) substrates was studied in detail. The films were prepared through sol-gel spin-coating method with variation in coating parameters viz, the thickness of the film and the post annealing temperature. The thickness of the films was measured using Stylus profilometer. The resistivity of the film, as a function of film thickness, under the illumination of UV, visible light, and dark conditions was found using the four-probe method. The results show that the resistivity of the film decreases with increase in thickness of the film. The decrease in resistivity of the film is attributed to increase in cross-sectional area and rearrangement and removal of defects. Illumination of the samples under visible and UV light further decreases the resistivity of the film. The electrical resistivity of TiO 2 film coated on Si substrate was observed to be lesser than that of the glass substrate. Keywords TiO 2 thin films Á Glass and silicon substrates Á XRD Á Electrical properties Á Light illumination
Surface Morphology, Compositional, Optical and Electrical Properties of TiO2 Thin Films
Abstract: Titanium oxide (TiO2) thin films have been deposited on to glass substrate by spray pyrolysis deposition technique (SPDT). The surface morphological, structural, electrical and optical properties of the asdeposited TiO2 thin films have been investigated as a function of substrate temperature (Ts). The scanning electron micrographs of as-deposited films showed uniform surface of TiO2 thin films. Elemental analysis clearly showed that the grains were typically comprised of both Ti and O in the thin films. Strong diffraction peaks (101) and (200) at 25° and 48° respectively indicating TiO2 in the anatase phase .The peaks were found to shift slightly from their standard positions at higher Ts, and there was some deviation in the lattice parameters. The crystallite size is found to be around 13 nm. The optical transmission of the thin films was found to increase from 73 to 89 % and the band gap energy shifts from 3.64 to 3.40 eV with increase of Ts. The room temperature dc electrical resistivity varies from 42 to 27 ohm.cm for the thin films grown at different Ts.
The influence of annealing temperature on the structure, optical and electrical property of TiO 2 thin films with (101) preferential orientation were deposited on glass substrates by sol-gel technique has been studied. As-deposited films were amorphous, and the XRD studies showed that the formation of anatase phase was initiated at annealing temperature close to 400 °C. The grain size of the film annealed at 550 °C was about 22 nm. The transmission spectra, recorded in the UV visible range reveal a relatively high transmission coefficient (~70%) in the obtained films. The transmittance data analysis indicates that the optical band gap (E g ) is closely related to the annealing temperature, an indirect band gap ranging from 3.43 eV to 3.04 eV was deduced. The electrical resistivity measurement that were carried out in function of the annealing temperature showed a sharp decrease in resistivity was found to be 0.0802 .cm.