Raman Study of Novel Nanostructured WO₃ Thin Films Grown by Spray Deposition

Area of Science:

• Materials Science
• Nanotechnology
• Solid State Chemistry

Background:

• Tungsten oxide (WO3) thin films are crucial for gas sensing applications.
• Controlling film morphology and crystallinity is key to optimizing sensor performance.
• Spray deposition offers a scalable method for WO3 thin film fabrication.

Purpose of the Study:

• To investigate the impact of sprayed solution volume (film thickness) and precursor concentration on WO3 thin film properties.
• To analyze structural and morphological changes using Raman spectroscopy.
• To correlate these changes with potential gas sensing capabilities.

Main Methods:

• Spray deposition of WO3 thin films from precursor solutions of 0.05 M and 0.1 M concentrations.
• Variation of sprayed solution volume to control film thickness.
• Raman spectroscopy for detailed structural analysis.
• Scanning Electron Microscopy (SEM) for morphological characterization (implied).

Main Results:

• Increased film thickness significantly altered morphology but had minor effects on crystalline structure.
• Lower precursor concentration (0.05 M) resulted in thinner films with more defects and lower crystallinity.
• Thicker films (higher volume) and films from higher precursor concentration (0.1 M) exhibited improved crystallinity, sharper peaks, and reduced defects.
• Differences in Raman spectra correlated with variations in film morphology and structural order.

Conclusions:

• Film thickness and precursor concentration are critical parameters in tailoring WO3 thin film properties via spray deposition.
• Optimizing these parameters can lead to enhanced crystallinity and structural order, beneficial for gas sensor applications.
• Raman spectroscopy is a powerful tool for elucidating structural nuances in WO3 thin films.