Structural, Optical and Photacoustic Studies on Rf

8/2/2019 Structural, Optical and Photacoustic Studies on Rf

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STRUCTURAL, OPTICAL AND

PHOTACOUSTIC STUDIES ON RF

MAGNETRON SPUTTERED TITANIUM

DIOXIDE THIN FILMS

Presented by ,

Sivasankari.P M.sc , B.Ed , M.Phil

(Physics)Loyola Institute of Technology


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Introduction

To analyze structural & optical properties of TiO2

To measure the thickness of TiO2

To match the values of band gap with literature

values


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Properties of TiO2

Good Durability

High Refractive Index (2.49 : Anatase) ,(2.903 : Rutile)

High chemical resistance against solvent and acid

Tetragonal crystal structure

Good resistance against UV.


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Applications

Used as reflective coating for dielectric mirrors.

Most widely used white pigment because of its brightness and

very high refractive index.

Employed as a pigment to provide whiteness & opacity to

products such as paints , coating plastics , inks & tooth pastes.

Used in plastics and other products where it acts as a UV

reflector.


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Thin film preparation method

Thermal evaporation

Electron beam deposition

Sputtering

Pulsed laser deposition


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Sputtering technique

Sputtering deposition is a physical vapor deposition method

of depositing thin film by sputtering a block of source material

onto a substrate.

Substrate placed on the chamber will coat the film.

Generally uses organ plasma.

Sputtering used as the process to deposit the metal (Al) at the

layer during the fabrication of CD discs.


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Experimental Part


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Target Preparation

Two drops ofPVA has to be added with 50 ml of drops of distilledwater and make a solution.

42.86 g of TiO2 has to be taken and drop the solution on it by drop

wise to grind TiO2 as a fine powder using mortar & paste.

Keep it under the visible light illumination for 30 minutes.

Keep it under hydraulic pressure for about 3 minute & sinter to

510`C for 1 hour.

Remove target from furnace once it attains the room temperature.


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Characterization techniques


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The thickness of TiO2 thin film was measured

using SJ-301 Mututoyo Profilometer

S.No Thin film Thickness in m

1 TiO2 (Ts = 50C) 1.28

2TiO2 (Ts = 100C)

0.96

3TiO2 (Ts =1 50C)

0.94

4TiO2 (Ts = 200C)

0.92


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Structural Properties

The X-ray diffraction spectra of TiO2 thin film deposited at

different temperature by RF magnetron sputtering.


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Optical Characterization

TiO2 film deposited at 150C have band gap energy

as 3.44 ev & 3.50 ev.

Film deposited at Ts = 200C have band gap energy

3.65 ev which matches well with literature values.


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Absorbance (X) Vs Wavelength (Y)


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Transmittance (X) Vs Wavelength (Y)


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Photo acoustic Spectroscopy

Photo acoustic signal amplitude was measured for

different wavelength ranging from 300 to 1100 nm.

Ts = 150C , Prf= 150 watt , 170 watt , Eg = 3.44 ev ,

3.5 ev.

Ts = 200

C , Prf= 170 watt , Eg = 3.65 ev.


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Conclusion

Thickness measurements shows that thickness of TiO2 filmdecreases with increase in temperature.

XRD analysis show that TiO2 films are amorphous for AS deposited

films and changed into crystalline phase when they annealed athigher temperature.

UV-vis spectrum showed that TiO2 films are high transparent , itwas found that band gap of the film decreases with increase in

temperature.

Band gap was calculated using photo acoustic measurements and itwas compared with optical band gap values


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Thank you

Structural, Optical and Photacoustic Studies on Rf

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