The Effect of Various Precursors and Solvents on the Characteristics of Fluorine-doped Tin Oxide Conducting Glass Fabricated by Ultrasonic Spray Pyrolysis

Transparent conductive oxide (TCO) glass is one of most important components in dye-sensitized solar cell (DSSC) device. In addition to its high electrical conductivity, transparency is another important requirement that must be achieved in fabricating TCO. One TCO film is fluorine-doped tin oxide (FTO), which can be considered as the most promising substitution for indium-doped tin oxide (ITO), since the latter is very expensive. However, the fabrication techniques for TCO film need to be carefully selected; the synthesis parameters must be properly optimized to provide the desired properties. In this work, FTO glass has been fabricated by the ultrasonic spray pyrolisis technique with different precursors, i.e. tin (II) chloride dihydrate (SnCl₂.2H₂O) and anhydrous tin (IV) chloride (SnCl₄), as well as different solvents, i.e. ethanol and methanol. For both conditions, ammonium fluoride (NH₄F) was used as the doping compound. The resulting thin films were characterized by use of a scanning electron microscope (SEM), x-ray diffraction (XRD), ultraviolet-visible (UV-Vis) spectroscopy and a four-point probe test. The results of the investigation show that the highest transmittance of 88.3% and the lowest electrical resistivity of 8.44×10-5 ?.cm were obtained with the FTO glass processed with 20 minutes of spray pyrolysis deposition and 300^oC substrate heating, using SnCl₄ as the precursor and methanol as the solvent. It can be concluded that TCO fabrication with tin chloride precursors and ammonium fluoride doping using ultrasonic spray pyrolisis can be considered as a simple and low cost method, as well as a breakthrough in manufacturing conductive and transparent glass.

Ammonium fluoride doping; Anhydrous tin (IV) chloride precursor; Conductive glass; Electrical resistivity; Optical transmittance; Tin (II) chloride dihydrate precursor

On the basis of the investigation, it has been found that the use of different tin precursors and types of solvents during the spray pyrolysis technique using an ultrasonic nebulizer affected the characteristics of FTO films. In the case of the SnCl₂.2H₂O precursor, the use of an ethanol solvent produced better thin layer characteristics compared to the use of methanol. However, an opposite trend was observed for the SnCl₄ precursor, where a better quality FTO film was obtained by using methanol instead of ethanol. The optimum value achieved in the study was shown by FTO film fabricated with SnCl₄ precursor in a methanol solvent with an electrical resistivity value of 8.44×10-5 ?.cm and an optical transmittance value of 88.3%.

The authors would like to thank the Ministry of Research and Higher Education of the Republic of Indonesia for funding this research through an Indonesian Institute of Sciences (LIPI) Research Center for Metallurgy and Materials 2016 Thematic Grant, as well as a PUPT Research Grant No.2725/UN2.R3.1/HKP05.00/2017.

Agashe, C., Mahamuni, S., 2010. Competitive Effects of Film Thickness and Growth Rate in Spray Pyrolytically Deposited Fluorine-doped Tin Dioxide Films. Thin Solid Films, Volume 518(17), pp. 4868–4873

Arini, T., Yuwono, A.H., Lalasari, L.H., Sofyan, N., Firdiyono, F., Trisdianto, C.A., Fikri, D, Nararya, A., Subhan, A., Hudaya, C., 2016. The Influence of Deposition Time and Substrate Temperature During the Spray Pyrolysis Process on the Electrical Resistivity and Optical Transmittance of 2 wt% Fluorine-doped Tin Oxide Conducting Glass. International Journal of Technology, Volume 7(8), pp. 1335–1343

Banyamin, Z.Y., Kelly, P.J., West, G., Boardman, J., 2014. Electrical and Optical Properties of Fluorine Doped Tin Oxide Thin Films Prepared by Magnetron Sputtering. Coatings, Volume 4, pp. 732–746

Brousseau, J.-L., Bourquea, H., Tessiera, A., Leblanca, R.M., 1997. Electrical Properties and Topography of SnO₂ Thin Films Prepared by Reactive Sputtering. Applied Surface Science, Volume 108(3), pp. 351–358

Ganz, D., Reich, A., Aegerter, M.A., 1997. Laser Firing of Transparent Conducting SnO₂ sol–Gel Coatings. Journal of Non-Crystalline Solids, Volume 218, pp. 242–246

Gordillo, G., Moreno, L.C., de la Cruz, W., Teheran, P., 1994. Preparation and Characterization of SnO₂ Thin Films Deposited by Spray Pyrolysis from SnCl2 and SnCl4 Precursors. Thin Solid Films, Volume 252(1), pp. 61–66

Hassanien, A.E., Hashem, H.M., Kamel, G., Soltan, S., Moustafa, A.M., Hammam, M., Ramadan, A.A., 2016. Performance of Transparent Conducting Fluorine-doped Tin Oxide Films for Applications in Energy Efficient Devices Performance of Transparent Conducting Fluorine-doped Tin Oxide Films for Applications in Energy Efficient Devices. International Journal of Thin Films Science and Technology, Volume 5(1), pp. 55–65

Karlsson, S., Jonson, B., Wondraczek, L., 2012. Copper, Silver, Rubidium and Caesium Ion Exchange in Soda–lime–silica Float Glass by Direct Deposition and in Line Melting of Salt Pastes. Glass Technology-European Journal of Glass Science and Technology Part A, Volume 53(1), pp. 1–7

Korotcenkov, G., DiBattista, M., Schwank, J., Brinzari, V., 2000. Structural Characterization of SnO₂ Gas Sensing Films Deposited by Spray Pyrolysis. Material Science and Engineering B, Volume B 77, pp. 33–39

Moholkar, A.V., Pawar, S.M., Rajpure, K.Y., Almari, S.N., Patil, P.S., Bhosale, C.H., 2008. Solvent-dependent Growth of Sprayed FTO Thin Films with Mat-like Morphology. Solar Energy Materials and Solar Cells, Volume 92(11), pp. 1439–1444

Muranaka, S., Bando, Y., Takada, T., 1986. Preparation and Properties of Sb-doped SnO₂ Films by Reactive Evaporation. Bulletin of the Institute for Chemical Research, Kyoto University, Volume 64(4), p.1986

Muruganantham, G., Ravichandran, K., Saravanakumar, K., 2011. Effect of Solvent Volume on the Physical Properties of Undoped and Fluorine Doped Tin Oxide Films Deposited using a Low-cost Spray Technique. Superlattices and Microstructures, Volume 50(6), pp. 722–733

Noh, S.I., Ahn, H., Riu, D., 2012. Photovoltaic Property Dependence of Dye-sensitized Solar Cells on Sheet Resistance of FTO Substrate Deposited via Spray Pyrolysis. Ceramics International, Volume 38(5), pp. 3735–3739

Paraskevi, A., Munkegade, N., 2008. Structural and Sensing Properties of Nanocrystalline SnO₂ Films Deposited by Spray Pyrolysis from a SnCl₂ Precursor. Applied Physics A Material Science and Processing, Volume 91, pp. 667–670

Patnaik, P., 2003. Handbook of Inorganic Chemicals D. Penikas, ed., New York: The McGraw-Hill Companies, Inc.

Raabe, O.G., 1976. Generation of Aerosols of Fine Particles. In: Fine particles. Y.H. Liu (ed.), Academic Press, New York, pp. 57–110

Ray, S.C., Karanjai, M.K., Dasgupta, D., 1997. Preparation and Study of Doped and Undoped Tin Dioxide Films by the Open Air Chemical Vapour Deposition Technique. Thin Solid Films, Volume 307, pp. 221–227

Shamala, K.S., Murthy, L.C.S., Rao, K.N., 2004. Studies on Tin Oxide Films Prepared by Electron Beam Evaporation and Spray Pyrolysis Methods. Bulletin of Materials Science, Volume 27(3), pp. 295–301

Tatar, D., Turgut, G., Duzgun, B., 2013. Effect of Substrate Temperature on the Crystal Growth Orientation and Some Physical Properties of SnO2:F Thin Film Deposited by Spray Pyrolisis Technique. Journal of Physics, Volume 58, pp. 143–158

Trisdianto, C.A.,Yuwono, A.H., Arini, T., Sofyan, N., Fikri, D., Lalasari, L.H., 2016. Optical Transmittance, Electrical Resistivity and Microstructural Characteristics of Undoped and Fluorine-doped Tin Oxide Conductive Glass Fabricated by Spray Pyrolysis Technique with Modified Ultrasonic Nebulizer. International Journal of Technology, Volume 7(8), pp. 1316–1325

Zhao, H.L, Liu, Q.Y., Cai, Y.X., Zhang, F.C., 2008. Effects of Water on the Structure and Properties of F-doped SnO₂ Films. Materials Letters, Volume 62, pp. 1294–1296