Title: Effect of annealing on the physical properties of WO₃ thin films

Authors: M. Bujji Babu; D. Divya Dixit; K.V. Madhuri

Addresses: Thin Film Laboratory, Department of Sciences and Humanities, VFSTR University, Vadlamudi-522213, Guntur, AP, India ' Thin Film Laboratory, Department of Sciences and Humanities, VFSTR University, Vadlamudi-522213, Guntur, AP, India ' Thin Film Laboratory, Department of Sciences and Humanities, VFSTR University, Vadlamudi-522213, Guntur, AP, India

Abstract: Tungsten trioxide (WO₃) thin films were deposited by electron beam evaporation technique at an oxygen partial pressure of 2 × 10⁻⁴ mbar and at different substrate temperatures ranging from room temperature (RT) to 450°C. The films were annealed at 400°C about 2 hours and the properties were studied systematically. The x-ray diffraction studies show the diffraction peak of (320) at 2θ = 44.07° which indicate the orthorhombic phase of WO₃ and also the other peaks represent the hexagonal phase of WO₃. Due to annealing of the films, the monoclinic phase is also observed. The surface morphology of WO₃ thin films was investigated by using atomic force microscopy and scanning electron microscopy, which supports the above data. The energy-dispersive x-ray (EDX) compositional analysis confirmed the presence of W and O. The optical properties were studied by UV-VIS spectrophotometer and hence the bandgap values are calculated.

Keywords: tungsten trioxide thin films; annealing; structural; morphological; optical and compositional.

DOI: 10.1504/IJNBM.2017.089335

International Journal of Nano and Biomaterials, 2017 Vol.7 No.1, pp.56 - 69

Received: 01 May 2017
Accepted: 23 Aug 2017
Published online: 17 Jan 2018 *

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