Reference of Temperature and Time during tempering process for non-stoichiometric FTO films

Abstract

In order to enhance the mechanical strength of Low-E glass, Fluorine-doped tin oxide (FTO) films have to be tempered at high temperatures together with glass substrates. The effects of tempering temperature (600 °C ~ 720 °C) and time (150 s ~ 300 s) on the structural and electrical properties of FTO films were investigated. The results show all the films consist of non-stoichiometric, polycrystalline SnO2 without detectable amounts of fluoride. 700 °C and 260 s may be the critical tempering temperature and time, respectively. FTO films tempered at 700 °C for 260 s possesses the resistivity of 7.54 × 10−4 Ω•cm, the average transmittance in 400 ~ 800 nm of ~80%, and the calculated emissivity of 0.38. Hall mobility of FTO films tempered in this proper condition is mainly limited by the ionized impurity scattering. The value of [O]/[Sn] at the film surface is much higher than the stoichiometric value of 2.0 of pure crystalline SnO2.

Mutual Effects of Fluorine Dopant and Oxygen Vacancies on Structural and Luminescence Characteristics of F Doped SnO2 Nanoparticles

“…71-0652). No other phases corresponding to fluoride are detected, indicating that fluorine ions are incorporated into the SnO 2 crystal lattice, or that F content is too little to be detected [ 18 , 19 , 20 , 21 , 22 , 23 , 24 ].…”

“…Tin chloride pentahydrate (SnCl 4 ·5H 2 O) and ammonium fluoride (NH 4 F) were used as the starting material and F dopant source, respectively. Based on the references [ 21 , 22 , 24 , 26 , 27 ], the dopant content (at. % F to Sn) was designed as 0 at.…”

“…The radius of F − ( ≈ 1.33 Å) is slightly less than that of O 2− ( ≈ 1.40 Å) and electronegativity of F − ( ≈ 4.368) is more pronounced than O 2− ( ≈ 3.758). Therefore, it is much easier for F − to replace O 2− in the SnO 2 lattice and generate oxygen vacancies [ 18 , 19 , 20 , 21 , 22 , 23 , 24 ]. Shewale et al [ 6 ] obtained an intense violet emission at 404 nm with a shoulder peak at 396 nm of F doped SnO 2 (FTO) films deposited by advanced spray pyrolysis technique at low substrate temperature.…”

“…In general, the PL processes are measured mainly under the 325 nm wavelength excitation [ 20 , 21 , 22 , 23 , 24 , 25 ]. Actually, the emission wavelength of low pressure mercury vapor is about 254 nm in Fluorescent lamps.…”

Size- and density-controlled deposition of Ag nanoparticle films by a novel low-temperature spray chemical vapour deposition method—research into mechanism, particle growth and optical simulation

“…Therefore, the observed effect could be explained by an impact of the already formed Ag particles. This might result in a better adsorption of the precursor, a locally higher temperature due to much less heat emission of Ag than of the FTO (emissivity Ԑ Ag ≈ 0.01-0.03, (Committee, 2002) Ԑ FTO ≈ 0.38 (Yang et al, 2015)) or an autocatalytic effect. For the latter an exponential increase of the reaction rate is reported (Atkins and de Paula, 2010).…”