Gas-chromism in ultrasonic spray pyrolyzed tungsten oxide thin films

Bulletin of materials science

P S Patil¹ 

[1] Department of Physics, Shivaji University, Kolhapur 416 004, India$$Department of Physics, Shivaji University, Kolhapur 416 004, IndiaDepartment of Physics, Shivaji University, Kolhapur 416 004, India$$

关键词: Ultrasonic spray pyrolysis;    tungsten oxide;    thin films;    gas-chromism.;   

DOI  :  

学科分类：材料工程

来源: Indian Academy of Sciences

【 摘 要 】

A simple and inexpensive ultrasonic spray pyrolysis (USP) technique has been employed to deposit tungsten oxide (WO₃) thin films by spraying 2.0 mM aqueous ammonium metatungstate solution onto the amorphous glass substrates kept at 250°C. The films were further annealed at 400°C for 4 h in air. X-ray diffraction (XRD) technique was used to determine the crystallinity and to identify the WO₃ phases. It was found that the films were sub-stoichiometric, WO_{3â€�?�ð�?��?}. To study gas-induced properties, a catalyzing layer of platinum (Pt) was sputtered onto it. The gas-induced electrical and optical properties of Pt/WO₃/glass samples were studied and results reported. It was found that electrical resistivity decreased by a factor of 10 within 2 min and stabilized after 15 min, after H₂ gas exposure. Similarly the optical transmittance of the samples attenuated from 55% to 10% within 15â€�??20 min. The reversible changes in electrical resistivity and optical transmittance were observed when the samples were exposed to oxygen. The response times and sensitivity of the samples were estimated.

【 授权许可】

Unknown