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

Abstract

Transparent conductive oxide (TCO) glass is one of most important components in dyesensitized 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 (SnCl 2 .2H 2 O) and anhydrous tin (IV) chloride (SnCl 4 ), as well as different solvents, i.e. ethanol and methanol. For both conditions, ammonium fluoride (NH 4 F) 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 Ω.cm were obtained with the FTO glass processed with 20 minutes of spray pyrolysis deposition and 300 o C substrate heating, using SnCl 4 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.

Structural and morphological properties of SnO2:Sb:F thin films produced by spray pyrolysis technique at various substrate temperatures

“…So, substrate temperature is more important parameter for preferential orientation in depositing thin film. Moreover, the preferred orientations depend on compounds' source, solvent and growth parameters such as solution and deposition concentration [7,19,20]. The crystallite size (D) of these AFTO thin films is calculated using Debye-Scherrer's formula, D=0.9λ/(βcosθ) [8] where λ is the wavelength (λ=1.5418 Å), β means of the broadening of diffraction line measured at (FWHM) and θ is the Bragg angle.…”

“…Transparent on optical range, low resistivity conducting and wide optical band gap (Eg) (>3 eV) oxides (TCOs) have attracted the scientists due to their wide using in many research and industrial areas for example, lowemissivity glass [1], window defrosters [2], transparent anode layer for all general organic light emitting diodes [3] and optoelectronic devices [4][5] gas sensor [6], DSSC solar cell [7] and flat panel TV displays. This combination sort of transparency and conductivity isn't usually possible in intrinsic stoichiometric oxides; however, it is made in a non-stoichiometric composition or with appropriate dopants as Sb, F, Zn, Mo, Pr and Ta [8].…”

“…This combination sort of transparency and conductivity isn't usually possible in intrinsic stoichiometric oxides; however, it is made in a non-stoichiometric composition or with appropriate dopants as Sb, F, Zn, Mo, Pr and Ta [8]. So, from 1940 year to nowadays many studies on TCOs by using different methods and by changing the conditions required to prepare them have been making to improve properties of them [1][2][3][4][5][6][7][8][9].…”

A Study on Sb and F Doped Tin Oxide Thin Films Preparing in Condition of Different Temperature and Molarity and Their Physical Comparison

“…TCOs thin films have deposited with various technique for a long time. It can be given for example spray pyrolysis (Yuwono et al, 2017), spin coating (Kadhim et al, 2017), pulsed laser deposition (Martin et al, 2004), dip coating (Carvalho et al, 2012) and sputtering (Zhu et al, 2017) methods. Among them, it was found that spray pyrolysis method have interesting properties such as simple and inexpensive experimental setup, reproducibility, easily adding of doping materials, preparing thin films with high quality (Tripathi and Shukla, 2014).…”

“…The properties of TCOs thin films have been fabricated by spray can be changed with substrate temperature, spray time, spray flow rate, nozzle-substrate distance, precursors and solvents etc. (Yuwono et al, 2017). Here, we aimed to compare effect of substrate temperature and molarity on TCOs thin films by spray method (for example SnO 2 :Sb:F).…”