<abstract xmlns="http://www.w3.org/1999/xhtml">Na2WO4 films have been grown at 400 °C using thermal evaporation technique. Their structural properties were characterized by XRD, while their chemical composition was verified by both EDX and X-ray photoelectron spectroscopy (XPS). The evolution of crystallinity was studied as a function of film thickness that ranged from 500 nm to 3000 nm. The grain size increased with increasing film thickness. The surface morphology of the prepared films was studied using scanning electron microscope (SEM) and atomic force microscopy (AFM). It has been observed that the average transmittance of samples in the visible and near infrared range has varied from 90 % to 78 % with the film thickness. The optical band gap of the Na2WO4 films varied from 3.8 eV to 4.1 eV. The crystalline size increased with increasing thickness and showed better sensing response to gases. Thus, this study confirmed the possibility of using Na2WO4 thick films as a sensor element for detection of ethanol (C2H5OH), acetone (C3H6O) methanol (CH3OH) and ammonia hydroxide (NH4OH) vapor at room temperature, where thicker films exhibited sensing properties with a maximum sensitivity at 25 °C in air, especially for NH4OH.</abstract>

Na2WO4 films have been grown at 400 °C using thermal evaporation technique. Their structural properties were characterized by XRD, while their chemical composition was verified by both EDX and X-ray photoelectron spectroscopy (XPS). The evolution of crystallinity was studied as a function of film thickness that ranged from 500 nm to 3000 nm. The grain size increased with increasing film thickness. The surface morphology of the prepared films was studied using scanning electron microscope (SEM) and atomic force microscopy (AFM). It has been observed that the average transmittance of samples in the visible and near infrared range has varied from 90 % to 78 % with the film thickness. The optical band gap of the Na2WO4 films varied from 3.8 eV to 4.1 eV. The crystalline size increased with increasing thickness and showed better sensing response to gases. Thus, this study confirmed the possibility of using Na2WO4 thick films as a sensor element for detection of ethanol (C2H5OH), acetone (C3H6O) methanol (CH3OH) and ammonia hydroxide (NH4OH) vapor at room temperature, where thicker films exhibited sensing properties with a maximum sensitivity at 25 °C in air, especially for NH4OH.

Study of crystallographic, optical and sensing properties of Na2WO4 films deposited by thermal evaporation with several thickness

Atomic Energy Commission, Department of Physics

Materials Science-Poland

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Study of crystallographic, optical and sensing properties of NaWO films deposited by thermal evaporation with several thickness

Na2WO4 films have been grown at 400 °C using thermal evaporation technique. Their structural properties were characterized by XRD, while their chemical...

Study of crystallographic, optical and sensing properties of Na₂WO₄ films deposited by thermal evaporation with several thickness

Published Online: Dec 30, 2019

Page range: 590 - 598

Received: Oct 11, 2018

Accepted: Apr 23, 2019

DOI: https://doi.org/10.2478/msp-2019-0080

Keywords
NaWO films, thermal evaporation, sensing properties

© 2019 B. Abdallah et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Study of crystallographic, optical and sensing properties of Na2WO4 films deposited by thermal evaporation with several thickness

Published Online: Dec 30, 2019

Page range: 590 - 598

Received: Oct 11, 2018

Accepted: Apr 23, 2019

DOI: https://doi.org/10.2478/msp-2019-0080

KeywordsNaWO films, thermal evaporation, sensing properties

© 2019 B. Abdallah et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Study of crystallographic, optical and sensing properties of Na₂WO₄ films deposited by thermal evaporation with several thickness

Keywords
NaWO films, thermal evaporation, sensing properties