Titanium oxide thin layers deposed by dip-coating method: Their optical and structural properties

Hemissi, M.; Amardjia-Adnani, Hania; Plenet, J. C.

doi:10.1016/j.cap.2008.07.001

Cited by 32 publications

(20 citation statements)

References 11 publications

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“…In general, spray pyrolysis is an attractive processing technique owing to a number of advantages: (1) low operational costs, (2) simple facilities, (3) ambient operation, [24][25][26][27] (4) potential for mass production, 20 (5) reproducibility of films, (6) rapid film growth rates (up to 100 nm/s 28 ), and (7) large surface area coverage. [20][21][22][23] Despite its advantages, spray pyrolysis has been the subject of only two types of mechanistic modeling studies [29][30][31][32] and two reviews.…”

Section: Introductionmentioning

confidence: 99%

“…1. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15] Of the preceding, the methods for chemical vapor deposition (CVD) are the best known and most widely used thin film fabrication techniques [16][17][18][19] largely because, in addition to the abovementioned advantages, they are adapted easily to the coating of large surfaces. [20][21][22][23] CVD methods also have the advantage that they can be used both with and without a vacuum system, [24][25][26][27] which is not the case with physical vapor deposition (PVD) methods, which require vacuum conditions.…”

Section: Introductionmentioning

confidence: 99%

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Conceptual model for spray pyrolysis mechanism: fabrication and annealing of titania thin films

Nakaruk

Sorrell

2010

J Coat Technol Res

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The present work presents a comprehensive model of both processes and outcomes of the spray pyrolysis mechanism, which is based on wide-ranging experience gained from experimentation involving a range of parameters. The deposition temperature and initial droplet size are the main parameters controlling film properties, including mineralogy, surface morphology, thickness, and bonding; the effect of annealing on these properties also is considered. The model is supported experimentally through the processing of films aerosol and ultrasonically spray pyrolyzed at 350°C, followed by annealing for 12 h at 500°C in air. Assessment of the mineralogy, chemical bonding, and crystallinity/residual stress of the films involved glancing-angle X-ray diffraction and laser Raman microspectroscopy, Fourier transform infrared spectroscopy, and crossed polarizers with an optical microscope, respectively.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Conceptual model for spray pyrolysis mechanism: fabrication and annealing of titania thin films

Nakaruk

Sorrell

2010

J Coat Technol Res

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“…To achieve compact switching devices, a large nonlinear refractive index ͑n 2 ͒ is required. Although many materials with a higher nonlinear refractive index than silica have been reported [2,[4][5][6], there is a particular interest in those compatible with planar processing technologies, with minimal losses and absorption at a wide range of operating wavelengths, and good thermal and mechanical robustness. Silicon provides one potential candidate [7,8] but exhibits strong free carrier and twophoton absorption limiting device performance.…”

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confidence: 99%

Chi 3 dispersion in planar tantalum pentoxide waveguides in the telecommunications window

2009

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We report on the dispersion of the third-order nonlinear susceptibility ( ͑3͒ or "Chi 3") in planar Ta 2 O 5 waveguides in the telecommunications spectral window. We utilize the observation of third-harmonic generation under ultrashort pulsed excitation as a reference-free characterization method of ͑3͒ and obtain a large nonlinear coefficient, 2 ϫ 10 −13 esu, at 1550 nm. Our observation of efficient third-harmonic generation in Ta 2 O 5 waveguides in the telecoms window reveals the potential of this material system in high-speed integrated nonlinear optical switches. © 2009 Optical Society of America OCIS codes: 160.4330, 230.7390, 190.2620 Fast low-power all-optical switches are a key component for high-bit-rate communication systems. Silica optical fibers are currently used owing to their low loss. However, the small nonlinear refractive index of silica [1-3] requires high switching powers and very long interaction lengths. To achieve compact switching devices, a large nonlinear refractive index ͑n 2 ͒ is required. Although many materials with a higher nonlinear refractive index than silica have been reported [2,4-6], there is a particular interest in those compatible with planar processing technologies, with minimal losses and absorption at a wide range of operating wavelengths, and good thermal and mechanical robustness. Silicon provides one potential candidate [7,8] but exhibits strong free carrier and twophoton absorption limiting device performance. Chalcogenide (e.g., As 2 S 3 ) glass is an alternative that does not exhibit two-photon absorption [9][10][11][12]; however, it has a relatively low damage threshold (9 GW/ cm 2 [13]) compared to Ta 2 O 5 [14]. Both of the above two examples have large normal material dispersion, which can be detrimental to wavelength division multiplexing applications but can be compensated by adjusting the waveguide geometry dimensions [7][8][9][10][11][12]. Here we investigate Ta 2 O 5 rib planar waveguides as an alternative for compact optical devices with a small effective area that could enable the exploitation of nonlinear effects at low light intensity in the telecoms window. Ta 2 O 5 has been widely used as a high dielectric gate material for microelectronic devices, and multilayer dielectric mirrors, and more recently it was shown to possess a high nonlinear refractive index at 800 nm [1,14].Silicon dioxide ͑SiO 2 ͒ clad Ta 2 O 5 planar rib waveguides are grown following the methodology in [15]. We examine the nonlinear optical properties of 5-mm-long waveguides with 750 nm core thickness and 2.5 m (sample A) and 18 m (sample B) width. Figure 1 shows a cross-sectional scanning electron microscope view of two waveguides. The samples are optically excited using an optical parametric amplifier tunable in the near IR (280 fs pulses) with no laser-induced damage to the waveguides.We characterize the nonlinear optical properties of the rib waveguides by spectrally and spatially resolving the guided optical modes at the end face of the rib structure in both the near-IR an...

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“…A number of techniques have been used to deposit TiO 2 films: direct current reactive magnetron sputtering and thermal annealing method [4], pressing method [5] and dip coating [6]. Another method of influencing the properties of TiO 2 films is by doping with elements like indium (In) and chromium (Cr) [7] cadmium (Cd), cesium (Ce) and iron (Fe) [8] on TiO 2 films obtained by r.f sputtering.…”

Section: Introductionmentioning

confidence: 99%

Structural and Optical Characterization of Nitrogen-doped TiO<SUB>2</SUB> Thin Films Deposited by Spray Pyrolysis on Fluorine Doped Tin Oxide (FTO) Coated Glass Slides

Ayieko¹,

Musembi²,

Waita³

et al. 2012

IJEE

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Undoped and nitrogen-doped titanium dioxide (TiO2) thin films of 400 nm thick deposited by spray pyrolysis were structurally and optically characterized. The effect of substrate temperature on the optical properties of the films was also investigated. Structural studies of the films were undertaken by X-ray diffraction (XRD). Energy dispersive X-ray (EDX) spectrum analysis was used to confirm the presence of nitrogen atoms in the film after doping. The optical properties such as refractive index (n), energy band gap (Eg) and Urbach energy (Eu) were determined from spectrophotometric measurements of reflectance and transmittance for both undoped and doped films. The Undoped films had an energy band gap of 3.25 eV while the doped films had band gap of 2.90 eV. The Urbach energy increased from 1.00 eV for undoped films to 1.04 eV for the nitrogen-doped films. The reduction in energy band gap and increase in Urbach energy was attributed to the introduction of nitrogen impurity tail states on either the conduction band or the valence band of the titanium dioxide.

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Titanium oxide thin layers deposed by dip-coating method: Their optical and structural properties

Cited by 32 publications

References 11 publications

Conceptual model for spray pyrolysis mechanism: fabrication and annealing of titania thin films

Conceptual model for spray pyrolysis mechanism: fabrication and annealing of titania thin films

Chi 3 dispersion in planar tantalum pentoxide waveguides in the telecommunications window

Structural and Optical Characterization of Nitrogen-doped TiO<SUB>2</SUB> Thin Films Deposited by Spray Pyrolysis on Fluorine Doped Tin Oxide (FTO) Coated Glass Slides

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