Study of structural, electrical and optical properties of vanadium oxide condensed films deposited by spray pyrolysis technique

Abstract

Vanadium oxides condensed films are prepared on glass substrates, using spray pyrolysis (SP) technique. The effects of substrate temperature, vanadium concentration in initial solution and the solution spray rate on the nano-structural, electrical, and optical properties of deposited films were investigated. Characterizations of the samples were performed using X-ray diffraction (XRD), scanning electron microscopy (SEM), and UV-Vis spectroscopy methods. The type and concentration of the charge carriers were determined and measured by Hall effect experiment. XRD patterns showed that the prepared films had polycrystalline structure, mostly tetragonal b-V 2 O 5 and V 4 O 9 phases with the preferred orientation along (200) direction. The Hall effect experiment revealed that all samples were n-type, except the ones deposited at substrate temperatures T sub = 300°C and T sub = 450°C, vanadium concentration 0.1 mol/L and solution spray rate 10 mL/min. The charge carrier concentrations obtained were in the range 10 16 -10 18 cm -3 . The lowest sheet resistance (R s ) was obtained for the samples prepared at T sub = 450°C, vanadium concentration 0.05 mol/L and solution spray rate 10 mL/min. It was also found that the optical transparency of the samples changed from 20% to 75% and the optical band gap of the samples was from 2.22 eV to 2.58 eV, depending on the deposition conditions.

Electronic Structure of C60/Zinc Phthalocyanine/V2O5 Interfaces Studied Using Photoemission Spectroscopy for Organic Photovoltaic Applications

“…At a critical temperature, crystallographic transformation shows that vanadium oxide accompanies a reversible semiconductor-to-metal transition that alters its optical and electrical properties [ 16 ]. Among the possible compounds of vanadium oxides, the stable V 2 O 5 phase possesses a wide optical band gap, good chemical and thermal stability, and excellent thermoelectric properties, which suggest that V 2 O 5 is a potential candidate in several applications including electro-chromic displays, gas sensing, and optoelectronic devices [ 17 , 18 , 19 , 20 ]. Different deposition techniques such as spray pyrolysis, ultrasonic spray pyrolysis, spin coating, thermal evaporation, electron beam evaporation, radio frequency sputtering, dc magnetron sputtering, sol-gel, and chemical vapor deposition have been used to deposit vanadium oxide thin films in order to improve the optical and electrical properties of transparent conductive oxides (TCOs).…”

Chemical Synthesis of Vanadium Oxide (V2O5) Nanoparticles Prepared by Sodium Metavanadate

“…Meaningful differences between the properties of different phases of vanadium oxides like VO, VO 2 , V 2 O 3 and V 2 O 5 depend on their structure, which determines other properties [16,17]. Different forms of vanadium oxides can be obtained by changing the deposition process parameters, or by post-process treatment, e.g., additional annealing [18]. From the application point of view, the most interesting vanadium oxides are VO 2 and V 2 O 5 .…”

Role of Polyvinylpyrrolidone (PVP) on Controlling the Structural, Optical, and Electrical Properties of Vanadium Pentoxide (V2O5) Nanoparticles

“…With increasing molar concentration, more oxygen vacancies are favorable, which leads to an increase in the width of localized states and hence to a decrease in bandgap energy. This reduction of bandgap energy can also be attributed to grain growth . The relationship between the bandgap and the particle size is given by the effective mass approximation (Eqn.…”

“…This reduction of bandgap energy can also be attributed to grain growth. [57,58] The relationship between the bandgap and the particle size is given by the effective mass approximation (Eqn. (3).…”