An investigation of the Nb doping effect on structural, morphological, electrical and optical properties of spray deposited F doped SnO₂ films

Abstract

F and Nb + F co-doped SnO2 thin films were deposited on glass substrates by the spray pyrolysis method. The microstructural, morphological, electrical and optical properties of the 10 wt% F doped SnO2 (FTO) thin films were investigated specifically for niobium (Nb) doping in the range of 0–4 at.% with 1 at.% steps. As shown by the x-ray diffraction patterns, the films exhibited a tetragonal cassiterite structure with (200) preferential orientation. It was observed that grain sizes of the films for (200) and (301) peaks depended on the Nb doping concentration and varied in the range of 25.11–32.19 and 100.6–183.7 nm, respectively. The scanning electron microscope (SEM) micrographs showed that the FTO films were made of small pyramidal grains, while doubly doped films were made of small pyramidal grains and big polyhedron grains. From electrical studies, although 1 at.% Nb doped FTO films have the lowest sheet resistance and resistivity values, the highest figure-of-merit and optical band gap values obtained for FTO films were 16.2 × 10−2 Ω−1 and 4.21 eV, respectively. Also, infrared reflectivity values of the films were in the range of 97.39–98.98%. These results strongly suggest that these films are an attractive candidate for various optoelectronic applications and for photothermal conversion of solar energy.

Mechanisms of Ion Detection for FET-Sensors Using FTO: Role of Cleaning Process, pH Sequence and Electrical Resistivity

“…They were deposited on glass by spray pyrolysis technique. This technique makes possible a good control of the sheet resistance of the films besides a production of a crystalline material with heterogeneous grain sizes distribution 37,38 . Thin film samples of different nominal sheet resistance of 5~10 Ω/sq (named S10), 21 Ω/sq (named S21) and 80~100 Ω/sq (named S100) were used in the experiments.…”

“…The advantages of using this material rely on its physical/chemical characteristics. For example: FTO is a n-type semiconductor with a large band gap (between 3.9~4.6 eV) [36][37][38] ; when produced by spray pyrolysis method, FTO presents interesting, very promising and useful physicalchemistry characteristics such as potential to be miniaturized, high transparence on visible spectrum region, high surface area, large conductivity range, mechanical hardness, thermal stability and biocompatibility.…”

Influencia de la potencia de deposición en las propiedades eléctricas y ópticas de películas delgadas de Sn1-xO2Nbx obtenidas por pulverización catódica

“…There are many experimental techniques available to prepare undoped and doped SnO 2 , such as pulser laser deposition, spray pyrolysis, reactive evaporation, and sputtering [20][21][22]. The sputtering technique is very controllable, reproductible and has high growth rates.…”

“…Many papers have described the effect of Nb doping on the physical properties of SnO 2 [21][22][23]. However, in this paper a systematic analysis is presented of the variation of the structural, optical and electrical properties of Sn 1-x O 2 Nb x thin films deposited by magnetron-sputtering technique, by changing the deposition power.…”

“…Table 1 shows the values, and Figure 2(a) The reflection intensities from each peak contain information related to the preferential or random growth of polycrystalline thin films, which is studied by calculating the texture coefficient TC(hkl) for the planes using the Eq. (3) [21].…”