Gas-sensing performance of WS2/WO3 binary thin films for methane and hydrogen detection

• Published in: Bulletin of materials science Vol. 47; no. 3; p. 153
• Main Authors: Salamatizadeh, R, Adelifard, M, Ketabi, S A
• Format: Journal Article
• Language: English
• Published: Bangalore Indian Academy of Sciences 16.07.2024; Springer Nature B.V
• Subjects: Accident prevention; Annealing; Chemistry and Materials Science; Electrical properties; Electrical resistivity; Engineering; Gases; Glass substrates; Hydrogen; Investigations; Materials Science; Methane; Molecular weight; Morphology; Optical properties; Semiconductors; Sensors; Structural analysis; Sulfur; Synthesis; Temperature; Thin films; Tungsten disulfide; Tungsten oxides; WO; gas sensing; structural characterization; WS; electrical conductivity; sulphurization
• ISSN: 0973-7669; 0250-4707; 0973-7669
• DOI: 10.1007/s12034-024-03265-6

This study presents the synthesis and characterization of WS 2 /WO 3 binary thin films with varying sulphur to tungsten ( S / W ) molar ratios ([S]/[W] = 6 and 18 at%) for gas-sensing applications. The films were obtained by annealing sprayed layers in a sulphur atmosphere. The structural, morphological, optical, electrical and gas-sensing properties of the films were investigated. X-ray diffraction analysis revealed that the as-deposited films exhibited an amorphous nature, while annealing in a sulphur atmosphere resulted in the formation of a mixed-phase WS 2 /WO 3 structure. Surface morphology studies showed changes associated with the sulphur concentration in the spray solution. Electrical characterization indicated p-type conductivity for all films, with a decrease in electrical resistivity as the sulphur-to-tungsten molar ratio increased. Gas-sensing experiments were performed to evaluate the detection of methane (CH 4 ) and hydrogen (H 2 ) gases. The pressure changes of 1.5 and 12.37 kPa were taken into account for methane gas and hydrogen gas, respectively. These pressure changes are equivalent to a concentration of 10 ppm for each gas. The WS 2 /WO 3 films exhibited high sensitivity, with the highest values observed at approximately 70% for CH 4 and 85% for H 2 gases. Overall, the successful synthesis and characterization of WS 2 /WO 3 binary thin films with tunable properties and superior gas-sensing performance suggest their potential for various gas-sensing applications.