Comparison of Optical Properties for SnO2 ,SnO2 : F and SnO2 :Sb Films Deposited on Glass Substrates

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WELCOME MESSAGE

NanoTR VII - 7th_{Nanoscience and Nanotechnology Conference}

PB 1

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Poster Presentations

Poster Session 1

THEME A

Nanomaterials; Nanoparticles, Nanocrystals, Nano-porous

materials, Molecular and supramolecular Materials

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P1.A. 3

Comparison of Optical Properties for SnO

2

, SnO

2

: F and SnO

2

:Sb Films Deposited on Glass

Substrates

Güven Turgut1*_{, Demet Tatar}1_, 2_{, Ahmet Battal}3_{and Bahattin Düzgün}1 1_{K. K. Education Faculty, Department of Physics, Ataturk University, Erzurum 25240, Turkey}

2_{Health services vocational high school,} _{76300, Turkey}

2_{Education Faculty, Department of Science Education, Mus Alparslan University, Mus 49100, Turkey}

Abstract— Thin films of undoped, 20 wt. % flourine-doped and 2 wt. % antimony-doped tin oxide on glasses at 410 ( 5) C were prepared by spray pyrolysis technique. The effect of 20 wt. % fluorine and 2 wt. % antimony doping on the optical properties of tin oxide thin films were investigated. From the optical studies, it was found that the transmittance of undoped film increased from 52.46 % to a maximum 78 % and 69,56 % for 20 wt. % fluorine-doped and 2 wt. % antimony-doped film, respectively.

The undoped stoichiometric SnO2 films have very high

electrical resistivity because of their low intrinsic carrier density and mobility [1]. Therefore the challenge is to prepare non-stoichiometric doped thin films. The conductivity of weakly nonstoichiometric tin oxide films is supposed to be due to doubly ionized vacancies serving as donors [2]. Dopants as antimony (Sb), indium (In), and fluorine (F), are frequently used. The fluorine and low concentrations of Sb doped tin oxide, being an n-type, wide band gap semiconductor ( 3 eV) with special properties, high transmittance in the visible range and high reflectance in the infrared, excellent electrical conductivity, greater carrier mobility and good mechanical stability are used in different devices like solar cells as transparent, protective electrodes [3], flat panel collectors as spectral selective windows, sensors for detection of gases, sodium lamps, gas sensors, and varistors [4–6]. Undoped tin oxide (TO), fluorine doped tin oxide (FTO) and antimony doped tin oxide (ATO) thin films have been prepared by various techniques, such as chemical vapour deposition, metalorganic deposition, rf sputtering, sol– gel, and spray pyrolysis [7–9]. Spray pyrolysis is used to prepare films because of its simplicity, cheapness and commercial viability [10,11]. Moreover, the spray pyrolysis technique is well suited for the preparation of doped tin oxide thin films because of it is ease to adding various doping materials, controlling the texture via various deposition temperatures and mass production capability for uniform large area coatings.

The prime aim of this work is to produce high transmission in SnO2 thin films by cost-effective chemical spray pyrolysis

technique. Hence undoped, 20 wt. % F and 2% wt. Sb doped tin oxide thin films were deposited on glass substrates at 410 ( 5) C were prepared by spray pyrolysis technique.

The optical properties of the TO, FTO and ATO thin films were studied in the UV-Vis spectrophotometer (Perkin Elmer, Lambda 35).

After the film deposition with spray pyrolysis, it was observed that the colour of the films varied from milky white for undoped SnO2 to grayish white for 20 wt. % F doped SnO2

and light blue for 2 wt. % Sb doped SnO2.

The transmission spectra of the films was shown in Fig 1. It was observed that visible transmittance would increase with flourine or antimony doping of tin oxide. The maximum transmittance observed for the TO, FTO and ATO thin films was 52,46%, 77,39% and 69,56%, respectively at the wavelength 800nm. The figure clearly shows the increase in transmittance due to 20 wt. % F and 2 wt. % Sb doping at visible range of wavelength. Highest transmittance was obtained in FTO films, whereas a lower transmittance was observed in TO films. This important variation could be due to the optical scattering by doping of TO films in this work.

Fig. 1. Comparison of transmittance spectra of undoped, fluorine doped and antimony doped SnO2films

*Corresponding author: guventurgut@atauni.edu.tr

[1] A.V. Moholkar, et. al. Applied Surface Science 255 9358–9364 (2009). [2] G. Turgut, et. al. 6th_{Nanoscience and Nanotechnology Conference June}

15-18 370 (2010).

[3] S. Colen, Thin Solid Films 77 127 (1981). [4] P.S. Patil, et. al. Thin Solid Films 437 34 (2003). [5] A. Dima, et. al. Thin Solid Films 427 427 (2003). [6] D.S. Lee, et. al. Thin Solid Films 416 271 (2002).

[7] J. Kane, H.P. Schweizer, J. Electrochem. Soc. 123 270 (1976). [8] T.N. Blanton, M. Lelental, Mater. Res. Bull. 29 537 (1994). [9] K.Y. Rajpure, et. al. Mater. Chem. Phys. 64 184 (2000). [10] P.S. Patil, Mater Chem Phys. 59 158 (1999).