Preparation and Microstructure Evolution of Both Freestanding and Supported TiO2 Thin Films

2002 ◽  
Vol 17 (6) ◽  
pp. 1520-1528 ◽  
Author(s):  
Chen-Lung Fan ◽  
Daniel Ciardullo ◽  
Jay Paladino ◽  
Wayne Huebner
Keyword(s):  
Thin Films ◽  
Heat Treatment ◽  
Grain Size ◽  
Grain Growth ◽  
Anatase Phase ◽  
Rutile Phase ◽  
Tio2 Thin Films ◽  
Cover Glass ◽  
Citrate Complex ◽  
Phase Development

Thin films of TiO2 were fabricated by spin-coating silicon wafers and cover glass with a titanium citrate complex precursor. The grain growth and phase development of both freestanding and supported films were studied using a combination of atomic force microscopy, x-ray diffraction, and transmission electron microscopy. Freestanding films prepared at 400 °C possess only the anatase phase, while supported films treated under the same conditions formed a small amount of the rutile phase. After heat treatment at various temperatures, results indicated that porosity was introduced into the films when the grain size grew close to the film thickness. Grain growth studies show that the grain size of the freestanding film underwent a drastic increase during the transformation from anatase to rutile. The grain size of the supported films did not show an abrupt change upon heat treatment. The grain size of the freestanding films treated at 900 °C was approximately three times larger than that of the supported films.

scholarly journals Effect of Substrate Temperature and Target-Substrate Distance on Growth of TiO2 Thin Films by Using DC- Reactive Sputtering Technique

2014 ◽  
Vol 17 (49) ◽  
Author(s):  
Laith Rabih ◽  
Sudjatmoko ◽  
Kuwat Triyana ◽  
Pekik Nurwantoro
Keyword(s):  
Thin Films ◽  
Grain Size ◽  
Electrical Properties ◽  
Substrate Temperature ◽  
Tio2 Film ◽  
Anatase Phase ◽  
Optical And Electrical Properties ◽  
Tio2 Thin Films ◽  
Weight Percentage ◽  
Substrate Distance

Titanium oxide (TiO2) thin films have been deposited by a DC sputtering technique onto microscope glass slides. The effect of substrate temperature (Ts) and target-substrate distance (Dts) on some optical and electrical properties have been studied each individually. The structure of TiO2 thin films has been improved and became more crystalline when Ts has been increased (from 150 ºC to 250 ºC). The conductivity (ϭ), deposition rate (DR) and average values of grain size (G.S) have been increased with increasing Ts while the values of band gap (Eg) and weight percentage of the anatase phase (WA) have been decreased. The thickness of TiO2 film has been increased from 920 nm to 960 nm with increase Ts while it has been decreased from 960 nm to 680 nm with increase Dts (from 25mm to 35mm). As Dts has been increased, the conductivity ϭ, thickness (d) and average values of grain size have been decreased. The decreasing of conductivity at Dts=35 maybe attributes to increase the weight percentage of the rutile phase (WR). The XRD results show that the TiO2 structure phase has been varied. The results show that the optical and electrical properties of TiO2 film affected by changes the condition parameters especially Ts and Dts as well as the density and energy of the impinging atoms. The surface morphology and component of TiO2 thin films, resistance, optical transmittance and structure of film were characterized by SEM (EDX), I-V meter, UV-VIS spectrophotometer and XRD respectively.

Thermally Controlled Crystallization of Electrospun TiO2 Nanofibers

2010 ◽  
Vol 71 ◽  
pp. 80-85 ◽  
Author(s):  
Hyoung Jun Park ◽  
Wolfgang M. Sigmund
Keyword(s):  
Heat Treatment ◽  
Photocatalytic Activity ◽  
Anatase Phase ◽  
Rutile Phase ◽  
X Ray Diffraction ◽  
Tio2 Nanofibers ◽  
Phase Development ◽  
Transmission Electron ◽  
Controlled Crystallization ◽  
Polymorphic Structure

The anatase phase of TiO2 has been of great interest due to its photocatalytic activity. For enhanced photocatalytic activity, the polymorphic structure of anatase phase and the rutile phase was pursued to form the semiconductor-semiconductor junction, which could even further enhance photocatalytic activity. TiO2 nanofibers with large specific surface area were fabricated via electrospinning from ethanol-based sol while the phase development was controlled by heat treatment. TiO2 fibers were characterized by x-ray diffraction (XRD) and transmission electron microscopy (TEM) for the crystalline phase and its microstructure, respectively. Among different heat treatment temperatures tested, 700°C was found to have the smallest grains while having both semiconductor, i.e. rutile and anatase available. TiO2 calcined at 800°C also achieved the polymorphic structure of anatase and rutile phases, however showed significant grain growth.

Effect of Heat Treatment on Optical Properties of Cold Spray TiO2 Coated Glass

2009 ◽  
Vol 79-82 ◽  
pp. 803-806
Author(s):  
Jing Kai Yang ◽  
Hong Li Zhao ◽  
Yan Li Liu ◽  
Fu Cheng Zhang
Keyword(s):  
Thin Films ◽  
Heat Treatment ◽  
Optical Properties ◽  
Cold Spray ◽  
Anatase Phase ◽  
Float Glass ◽  
Light Transmittance ◽  
Tio2 Thin Films ◽  
Coated Glass ◽  
Glass Substrates

The cold spray TiO2 thin films were deposited on 5mm-thick float glass substrates using the sol containing nano-anatase TiO2. The effects of different heat treatment temperatures on optical properties were discussed. The properties of xerogel powder were analyzed using TG-DSC, the morphology and structure of TiO2 thin films were characterized by FESEM and XRD, the transmittance and absorption of TiO2 coated glass were investigated by UV-vis spectrophotometer. The results reveal that TiO2 in the film is still anatase phase after heat treatment at 350°C and 500°C. With the annealing temperatures increasing from 20°C to 500°C, the average crystal size increases just from 21.4 nm to 23.9nm, UV absorption of TiO2 coated glass increases from 2.2 to 2.7, visible light transmittance is high to about 80%.

scholarly journals Optimization of Photogenerated Charge Carrier Lifetimes in ALD Grown TiO2 for Photonic Applications

Nanomaterials ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1567
Author(s):  
Ramsha Khan ◽  
Harri Ali-Löytty ◽  
Jesse Saari ◽  
Mika Valden ◽  
Antti Tukiainen ◽  
...  
Keyword(s):  
Thin Films ◽  
Heat Treatment ◽  
Carrier Lifetime ◽  
Transient Absorption ◽  
Anatase Phase ◽  
Atomic Layer ◽  
Transient Absorption Spectroscopy ◽  
High Temperature Treatment ◽  
Tio2 Thin Films ◽  
Long Lifetime

Titanium dioxide (TiO2) thin films are widely employed for photocatalytic and photovoltaic applications where the long lifetime of charge carriers is a paramount requirement for the device efficiency. To ensure the long lifetime, a high temperature treatment is used which restricts the applicability of TiO2 in devices incorporating organic or polymer components. In this study, we exploited low temperature (100–150 °C) atomic layer deposition (ALD) of 30 nm TiO2 thin films from tetrakis(dimethylamido)titanium. The deposition was followed by a heat treatment in air to find the minimum temperature requirements for the film fabrication without compromising the carrier lifetime. Femto-to nanosecond transient absorption spectroscopy was used to determine the lifetimes, and grazing incidence X-ray diffraction was employed for structural analysis. The optimal result was obtained for the TiO2 thin films grown at 150 °C and heat-treated at as low as 300 °C. The deposited thin films were amorphous and crystallized into anatase phase upon heat treatment at 300–500 °C. The average carrier lifetime for amorphous TiO2 is few picoseconds but increases to >400 ps upon crystallization at 500 °C. The samples deposited at 100 °C were also crystallized as anatase but the carrier lifetime was <100 ps.

Preparation and Characterization of TiO2 Photocatalytic Thin Film Prepared by Sol-Gel Dip Coating

2012 ◽  
Vol 476-478 ◽  
pp. 2398-2402
Author(s):  
Jiao Jiao Wang ◽  
Kai Zheng ◽  
Christian Rüssel ◽  
Wen Liang
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Rhodamine B ◽  
Uv Light ◽  
Anatase Phase ◽  
Sol Gel ◽  
Rutile Phase ◽  
Dip Coating ◽  
High Photocatalytic Activity ◽  
Tio2 Thin Films

Titanium dioxide thin films have been prepared from tetrabutyl-orthotitanate solution and methanol as a solvent by sol-gel dip coating technique. The thermal properties of TiO2 gel were analyzed by thermogravimetry and differential thermal analysis (TG-DTA). Structural properties of TiO2 thin films at different heat treatment temperatures were analyzed by X-ray diffraction (XRD), Infrared Raman spectroscopy and scanning electron microscopy (SEM). The results show that the TiO2 thin films crystallize in anatase phase at 400 °C and the crystallinity of anatase phase was improved with increasing temperature. The TiO2 thin films crystallize into the anatase-rutile phase at 600 °C and further into the rutile phase at 800 °C. The photocatalytic performance of TiO2 film was tested for the degradation of 2×10-5 mol/L Rhodamine B. The degradation of Rhodamine B solutions reached 0.9×10-5 mol/L after irradiated for 8 h under UV light. The TiO2 thin film exhibited relatively high photocatalytic activity towards degrading Rhodamine B.

LiNiO2 Thin Films Fabricated by Diffusion of Li on Ni Tapes

2007 ◽  
Vol 336-338 ◽  
pp. 505-508
Author(s):  
Cheol Jin Kim ◽  
In Sup Ahn ◽  
Kwon Koo Cho ◽  
Sung Gap Lee ◽  
Jun Ki Chung
Keyword(s):  
Thin Films ◽  
Heat Treatment ◽  
Grain Size ◽  
Sol Gel ◽  
Surface Oxidation ◽  
Cold Isostatic Pressing ◽  
Tube Furnace ◽  
Treatment Conditions ◽  
Average Grain Size ◽  
Cold Rolling And Annealing

LiNiO2 thin films for the application of cathode of the rechargeable battery were fabricated by Li ion diffusion on the surface oxidized NiO layer. Bi-axially textured Ni-tapes with 50 ~ 80 μm thickness were fabricated using cold rolling and annealing of Ni-rod prepared by cold isostatic pressing of Ni powder. Surface oxidation of Ni-tapes were conducted using tube furnace or line-focused infrared heater at 700 °C for 150 sec in flowing oxygen atmosphere, resulted in NiO layer with thickness of 400 and 800 μm, respectively. After Li was deposited on the NiO layer by thermal evaporation, LiNiO2 was formed by Li diffusion through the NiO layer during subsequent heat treatment using IR heater with various heat treatment conditions. IR-heating resulted in the smoother surface and finer grain size of NiO and LiNiO2 layer compared to the tube-furnace heating. The average grain size of LiNiO2 layer was 0.5~1 μm, which is much smaller than that of sol-gel processed LiNiO2. The reacted LiNiO2 region showed homogeneous composition throughout the thickness and did not show any noticeable defects frequently found in the solid state reacted LiNiO2, but crack and delamination between the reacted LiNiO2 and Ni occurred as the reaction time increased above 4hrs.

Homogeneous Al-Ti and Al-Ti-Si Thin Alloy Films

1985 ◽  
Vol 54 ◽  
Author(s):  
Albertus G. Dirks ◽  
Tien Tien ◽  
Janet M. Towner
Keyword(s):  
Thin Films ◽  
Heat Treatment ◽  
Grain Size ◽  
Electrical Resistivity ◽  
Phase Formation ◽  
Alloy Composition ◽  
Al Alloy ◽  
Second Phase ◽  
Alloy Films ◽  
Microstructure And Properties

ABSTRACTThe microstructure and properties of thin films depends strongly upon the alloy composition. A study was made of the metallurgical aspects of homogeneous Al alloy films, particularly the binary Al-Ti and the ternary Al-Ti-Si systems. Electrical resistivity, grain size morphology, second phase formation and electromigration have been studied as a function of the alloy composition and its heat treatment.

Structural Evolution and Optical Properties of TiO2 Thin Films Prepared by DC-Reactive Sputtering Technique

2013 ◽  
Vol 699 ◽  
pp. 789-794 ◽  
Author(s):  
Laith Rabih ◽  
Sudjatmoko ◽  
Kuwat Triyana ◽  
Pekik Nurwantoro
Keyword(s):  
Thin Films ◽  
Grain Size ◽  
Band Gap ◽  
Structural Evolution ◽  
Film Structure ◽  
Tio2 Thin Films ◽  
Glass Substrates ◽  
Alternative Material ◽  
Dc Sputtering Technique ◽  
Economical Alternative

Titanium dioxide (TiO2 ) thin films have been deposited on glass substrates under various conditions by using a homemade reactive DC sputtering technique. The TiO2 has unique characteristics and economical alternative material for transparent conductivity oxide thin films compared with other materials. In this study, titanium (Ti) has been used as a target while argon (Ar) and oxygen (O22</subthin films has been measured by using a calibrated I-V meter. On the other hand, the transparency, microstructure and component of TiO2 thin films have been investigated respectively by using UV-VIS spectrophotometer, XRD and SEM (EDX). The thickness of TiO2 films, the grain size and the band gap have been also successfully estimated. As a result, the conductivity of films increased for Dt at 1 hour to 3.5 hours and decreased for Dt at 4 hours. It means that the optimum Dt was at about 3.5 hours. It may be related to the thickness (structures) of the films. In addition, the thickness and grain size increased by increasing Dt, while the band gap decreased when the film structure changed from non-crystalline structure to crystalizing structure.

Ion Induced Grain Growth in Pd

1991 ◽  
Vol 235 ◽  
Author(s):  
D. A. Lilienfeld ◽  
P. Bøorgesen ◽  
P. Meyer
Keyword(s):  
Thin Films ◽  
Grain Size ◽  
Grain Growth ◽  
Low Temperatures ◽  
Nanocrystalline Materials ◽  
Ion Irradiation ◽  
Size Distributions ◽  
Careful Choice ◽  
Average Grain Size

ABSTRACTIon irradiation induced grain growth size distributions in Pd are examined at low temperatures. Two features are observed: 1) A majority of the grains saturate in size. 2) Some grains achieve sizes much larger than the average grain size and continue to grow with ion dose. However, by careful choice of ion mass and ion dose, it is possible to produce a sample possessing a monomodal grain size. This process will have applications in producing thin films of nanocrystalline materials.

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