Structural, electrical and optical properties of TiO2 doped WO3 thin films

Patil, Pramod S.; Mujawar, S.H.; Shinde, Pravin S.; Deshmukh, H.P.; Sadale, S.B.

doi:10.1016/j.apsusc.2005.03.074

Cited by 62 publications

(25 citation statements)

References 21 publications

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“…Other, supporting studies on the electrochromism in W-Ti oxide have been reported for films prepared by sputtering [16][17][18][19], chemical technology involving spraying [20][21][22] dipping [16,23] or spinning [24][25][26], electrodeposition [27,28] and anodization [29]. The enhanced stability has been investigated in depth in recent work on W-Ti oxide films made by sputtering [30,31] and chemical techniques [26].…”

Section: Introductionmentioning

confidence: 99%

Electrochromism in sputter-deposited W–Ti oxide films: Durability enhancement due to Ti

Arvizu

Triana

Stefanov

et al. 2014

Solar Energy Materials and Solar Cells

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Electrochromism in sputter-deposited W-Ti oxide films: Durability enhancement due to Ti. Solar Energy Materials and Solar AbstractThin films of W-Ti oxide were prepared by reactive DC magnetron sputtering and were characterized by Rutherford backscattering spectrometry, X-ray diffraction, scanning electron microscopy and atomic force microscopy. The electrochromic properties were studied by cyclic voltammetry in an electrolyte of lithium perchlorate in propylene carbonate and by optical transmittance measurements. The addition of Ti significantly promoted the amorphous nature of the films and stabilized their electrochemical cycling performance and dynamic range for electrochromism.

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Section: Introductionmentioning

confidence: 99%

Electrochromism in sputter-deposited W–Ti oxide films: Durability enhancement due to Ti

Arvizu

Triana

Stefanov

et al. 2014

Solar Energy Materials and Solar Cells

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“…Later, Wang and Hu successfully composed a TiO 2 -doped WO 3 film by spin coating and found that the Ti-addition stabilized the peroxotungstic acid in the spin coating solutions. 26 In 2005, Patil et al 27 prepared WO 3 -TiO 2 films via a spray pyrolysis method and discussed the improved electrochromic reversibility and coloration efficiency.However, in these earlier works the coloration efficiency has not improved significantly to the level where it can be used in a practical smart window. Indeed, in some cases certain levels of TiO 2 additions were detrimental to the coloration efficiency.…”

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confidence: 99%

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confidence: 99%

Electrochromic Enhancement of WO₃-TiO₂Composite Films Produced by Electrochemical Anodization

Gui

Blackwood

2014

J. Electrochem. Soc.

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An enhancement of the electrochromic properties of WO 3 thin films by the incorporation of TiO 2 is presented. The composite films are obtained by anodizing co-sputtered tungsten / titanium on conductive glass substrates in 1 M H 2 SO 4 solution containing 0.3 wt% NaF. As the titanium content is increased from 0 to 15 at.% a morphology evolution occurs, from nano-porous to nano-flakes and finally to nano-blocks interweaved with nano-pores. The nano-flakes, obtained at 10 at% Ti, proved to be the most conducive structure for the insertion and removal of Li + ions such that this composition exhibits transmittance regulation abilities of 58.5%, 72% and 77.7% at 550 nm, 632.8 nm and 800 nm respectively, which are more than a 25% improvement at all wavelengths over a pure WO 3 film formed in the same way. The WO 3 /TiO 2 film with addition of 10 at.% Ti also has faster coloration/bleaching times, especially in the critical near infrared region with values of 10 s / 64 s at 800 nm compared with 32 s / 90 s of a pure WO 3 thin film, as well as improved stability losing less than 5% of its capacity after 1000 switching cycles. and electrodeposition. 11,12 However, the electrochemical anodization method adopted in this work provides a simple and economic way of synthesizing targeted morphologies such as nanoporous or nanotube structures. Unfortunately there are still drawbacks when compared to vacuum deposited films, for instance the electrochemically prepared WO 3 has poorer reversibility and stability as well as a shorter optical modulation range. This has led to interest in mixed metal oxide composite systems to compensate for these eficiencies. [13][14][15][16][17][18][19] To date, there are many reports on the doping or mixing other oxides with WO 3 to improve its electrochromic properties, with oxides of barium, 20 cobalt, 21 nickel, 22 molybdenum 23 and most successfully titanium.24 Even a small quantity of the guest oxide has a profound effect on the host's optical properties. Hashimoto and Matsuoka first reported in 1991 that an amorphous WO 3 -TiO 2 film, produced by electron beam deposition method, exhibits a longer life-time than a pure tungsten oxide film. 24 Subsequently, in 1993, Gottsche et al. 25 compared the electrochromic properties of mixed WO 3 -TiO 2 thin films fabricated by sputtering and sol-gel techniques. These authors point out that the addition of TiO 2 with molar percentages ranging from 10% to 15% reduced the crystallinity of WO 3 host and led to significant structural changes. Later, Wang and Hu successfully composed a TiO 2 -doped WO 3 film by spin coating and found that the Ti-addition stabilized the peroxotungstic acid in the spin coating solutions. 26 In 2005, Patil et al. 27 prepared WO 3 -TiO 2 films via a spray pyrolysis method and discussed the improved electrochromic reversibility and coloration efficiency.However, in these earlier works the coloration efficiency has not improved significantly to the level where it can be used in a practical smart window. Indeed, in some cases cert...

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Section: Introductionmentioning

confidence: 85%

“…Anatase is proven recently as the most photocatalytically active and more ionic of the three polymorphs. In addition, the conduction band is better around 0.3 eV more positive than rutile phase [3].In practical technological applications, anatase TiO 2 is widely used for light emitting diodes, laser diodes and solar cells [4]. It shows magnificent performance when combined with organic dye in dye-sensitized solar cells (DSCs) which demonstrated by Gratzel [5][6].…”

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confidence: 97%

Influence of Different Solvents on the Formation of Uniform Titanium Dioxide (TiO<sub>2</sub>) Thin Film by Sol-Gel

Sahdan

Alias

Lias

et al. 2015

AMM

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Abstract. Uniform Titanium dioxide (TiO 2 ) thin film is essential for application in high performance solar cells. A low cost approach using TiO 2 nanopowder extracted from tin mining waste to deposit TiO 2 thin films is demonstrated in this paper. Furthermore, the influence of different solvents (ethanol, acetone, isopropanol and ethylene glycol) on the formation of uniform TiO 2 thin films in sol-gel technique is studied. The films were characterized by an atomic force microscope (AFM), ultra violet -visible spectrometer (UV-Vis) and a current-voltage (I-V) measurement system. The correlations of the structural, optical and electrical behavior to the type of solvent used were discussed in details. IntroductionTitanium dioxide (TiO 2 ) or known as titania is a unique IV-VI semiconductor where it has three different polymorps. The naturally occurring polymorph is brookite and extremely difficult to synthesize. While the most commonly researched polymorphs are anatase and rutile. When the sintering temperature is over 500°C, brookite will transform to anatase form [1]. The anatase will transform to rutile when the temperature is over 600°C [2]. Anatase is proven recently as the most photocatalytically active and more ionic of the three polymorphs. In addition, the conduction band is better around 0.3 eV more positive than rutile phase [3].In practical technological applications, anatase TiO 2 is widely used for light emitting diodes, laser diodes and solar cells [4]. It shows magnificent performance when combined with organic dye in dye-sensitized solar cells (DSCs) which demonstrated by Gratzel [5][6]. On the other hand, the emerging of organic solar cells also requires TiO 2 nanolayer to improve the solar cell performance [7]. TiO 2 films also reported to have possibility to reduce air pollution when it absorbed carbon monoxide (CO) when coat on buildings [8]. There are several more reports have been found on the relevance of TiO 2 for the application of high technological devices. Therefore, it is essential to study the process of synthesizing TiO 2 thin films to improve the performance and to reduce the processing cost for manufacturing.There are several methods to synthesize TiO 2 thin films such as r.f. sputtering [9], laser ablation [10] and chemical vapor deposition (CVD) [11]. However, these methods require expensive and sophisticated equipments where not only the return of investment (ROI) is longer, the mass production also will be an issue. Sol-gel spin coating is a cost effective method and capable for mass production [12]. In this paper, nano-TiO 2 powder which was synthesized from local tin mining waste has been used as the starting material. Our initial works has been reported by M.Z. Sahdan et al. [13] demonstrating the effects of mass concentration and catalyst volume on the uniformity and performance of the TiO 2 thin films. In this study, different solvents have been used to synthesize

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Structural, electrical and optical properties of TiO2 doped WO3 thin films

Cited by 62 publications

References 21 publications

Electrochromism in sputter-deposited W–Ti oxide films: Durability enhancement due to Ti

Electrochromism in sputter-deposited W–Ti oxide films: Durability enhancement due to Ti

Electrochromic Enhancement of WO₃-TiO₂Composite Films Produced by Electrochemical Anodization

Influence of Different Solvents on the Formation of Uniform Titanium Dioxide (TiO<sub>2</sub>) Thin Film by Sol-Gel

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Structural, electrical and optical properties of TiO2 doped WO3 thin films

Cited by 62 publications

References 21 publications

Electrochromism in sputter-deposited W–Ti oxide films: Durability enhancement due to Ti

Electrochromism in sputter-deposited W–Ti oxide films: Durability enhancement due to Ti

Electrochromic Enhancement of WO3-TiO2Composite Films Produced by Electrochemical Anodization

Influence of Different Solvents on the Formation of Uniform Titanium Dioxide (TiO<sub>2</sub>) Thin Film by Sol-Gel

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Electrochromic Enhancement of WO₃-TiO₂Composite Films Produced by Electrochemical Anodization