Impact of Ag on the Limit of Detection towards NH<sub>3</sub>-Sensing in Spray-Coated WO<sub>3</sub> Thin-Films
Anusha,
Aninamol Ani,
P. Poornesh,
Albin Antony,
Bhaghyesh,
Igor V. Shchetinin,
K. K. Nagaraja,
Saikat Chattopadhyay,
K. B. Vinayakumar
Affiliations
Anusha
Department of Physics, Manipal Institute of Technology, Manipal Academy of Higher Education, Manipal 576104, Karnataka, India
Aninamol Ani
Department of Physics, Manipal Institute of Technology, Manipal Academy of Higher Education, Manipal 576104, Karnataka, India
P. Poornesh
Department of Physics, Manipal Institute of Technology, Manipal Academy of Higher Education, Manipal 576104, Karnataka, India
Albin Antony
Department of Surface and Plasma Science, Faculty of Mathematics and Physics, Charles University, V Holešovičkách, Praha 8, 218000 Praha, Czech Republic
Bhaghyesh
Department of Physics, Manipal Institute of Technology, Manipal Academy of Higher Education, Manipal 576104, Karnataka, India
Igor V. Shchetinin
Department of Physical Materials Science, National University of Science and Technology “MISiS”, Leninskiy Pr. 4, 119049 Moscow, Russia
K. K. Nagaraja
Department of Physics, Manipal Institute of Technology, Manipal Academy of Higher Education, Manipal 576104, Karnataka, India
Saikat Chattopadhyay
Department of Physics, School of Basic Sciences, Manipal University Jaipur, Jaipur 303007, Rajasthan, India
K. B. Vinayakumar
Micro and Nano Fabrication Department, INL-International Iberian Nanotechnology Laboratory Avenida Mestre Jose Veiga, 4715-330 Braga, Portugal
Ag-doped WO3 (Ag–WO3) films were deposited on a soda-lime glass substrate via a facile spray pyrolysis technique. The surface roughness of the films varied between 0.6 nm and 4.3 nm, as verified by the Atomic Force Microscopy (AFM) studies. Ammonia (NH3)-sensing measurements of the films were performed for various concentrations at an optimum sensor working temperature of 200 °C. Enrichment of oxygen vacancies confirmed by X-ray Photoelectron Spectroscopy (XPS) in 1% Ag–WO3 enhanced the sensor response from 1.06 to 3.29, approximately 3 times higher than that of undoped WO3. Limit of detection (LOD) up to 500 ppb is achieved for 1% Ag–WO3, substantiating the role of Ag in improving sensor performance.
