Synthesis of electrochromic vanadium oxide by pulsed spray pyrolysis technique and its properties

Abstract

A new improved pulsed spray pyrolysis technique (PSPT) was employed to deposit a vanadium oxide (V2O5) thin film from a methanolic vanadium chloride precursor onto glass and conducting F : SnO2 coated glass substrates. The structural, morphological, electrical, optical and spectroscopic properties of the film deposited at 573 K were studied. Infrared spectroscopy and x-ray diffraction confirmed the presence of the V2O5 phase. The V2O5 film (thickness ∼118 nm) is polycrystalline with a tetragonal crystal structure. Scanning electron microscopy reveals compact granular morphology consisting of ∼80–100 nm size grains. The film is transparent in the visible region (average %T ∼70%) with an optical band gap energy of 2.47 eV involving both direct and indirect optical transitions. The room temperature electrical resistivity (conductivity) of the film is 1.6 × 108 Ω cm (6.25 × 10−9 S cm−1) with an activation energy of 0.67 eV in the temperature range 300–550 K. It exhibited cathodic electrochromism in the lithium containing electrolyte (0.5 M LiClO4 + propylene carbonate).

Temperature effect on structural and optical properties of V2O5 thin films prepared by spray pyrolysis technique

“…This morphology is very important because it allows the insertion of chemical species (gas, etc…). This helps to consider several applications for those layers especially in the field of electrochromism [22][23]. Figure 4 shows the optical transmission spectra of V2O5 thin layers at the initial state developed in different temperature.…”

Characterization of V2O5 nanorods grown by spray pyrolysis technique

“…Therefore, it is very important to choose the appropriate deposition parameters to prepare the vanadium oxide thin films for a certain application [9]. V 2 O 5 thin films have been prepared by different techniques including pulsed laser deposition [10], sol-gel [11,12], vacuum evaporation [13], magnetron sputtering [14], electron-beam evaporation [15], and spray pyrolysis [16]. Among the various deposition techniques for the preparation of vanadium oxide thin films, chemical spray pyrolysis technique is a relatively simple and inexpensive technique for large-area coatings.…”

Electrochromic properties of vanadium oxide thin films prepared by PSPT: Effect of substrate temperature

“…PSPT has several advantages such as simplicity, safety, low cost of the apparatus and raw materials as well as large scale deposition. EXPERIMENTAL V 2 O 5 thin films were deposited by PSPT onto both glass and FTO-coated glass substrates at different substrate temperatures (350, 400 and 450°C) as reported earlier [6]. In brief, the precursor solution was sprayed on to the pre-heated glass substrates maintained at a desired substrate in which 20 ml of methanolic VCl 3 solution was sprayed.…”