Tailoring of optical and gas sensitivity behaviors of WO3 films by low energy Ar+ ion implantation

In this paper we report the structural, optical and gas sensitivity behaviors of WO3 films implanted by 100 keV Ar+ ions. The films have been deposited on the unheated corning glass and n-type Si (100) substrates by thermal evaporation technique. The structural and vibrational properties of the pristine and implanted films have been thoroughly studied using X-ray diffraction patterns and Raman micrographs respectively. Optical transmittance and reflectance spectra of the films in the wavelength range 300 to 1000 nm have been measured. An increase in optical band gap from 2.90 to 3.49 eV has been observed with the increase in fluence from 3 x 10(15) to 1 x 10(17) cm(-2). It is also observed that implantation has caused enhancement in photoluminescence yield of the films. All films, especially the implanted films have shown good gas sensing behavior in methane environment. The film with a critical fluence of value 1 x 10(16) cm(-2) shows better optical as well as gas sensing behaviors and hence can have good device applications. (C) 2012 Elsevier B. V. All rights reserved.