Highly Tunable MOCVD Process of Vanadium Dioxide Thin Films: Relationship between Structural/Morphological Features...

Area of Science:

• Materials Science
• Solid State Physics

Background:

• Vanadium dioxide (VO2) monoclinic structures exhibit diverse functional properties.
• Thin film VO2 is critical for terahertz (THz) devices and sensors, requiring precise structural and morphological control.

Purpose of the Study:

• To achieve fine control over VO2 crystal habit using metal-organic chemical vapor deposition (MOCVD).
• To investigate the influence of deposition temperature on stabilizing specific monoclinic VO2 structures (P21/c or C2/m).

Main Methods:

• Metal-organic chemical vapor deposition (MOCVD) for VO2 thin film synthesis.
• Energy-dispersive X-ray (EDX) for compositional purity analysis.
• Field-emission scanning electron microscopy (FE-SEM) for morphology and thickness assessment.
• Terahertz (THz) time-domain spectroscopy for functional property validation.

Main Results:

• Demonstrated MOCVD's capability for fine control over VO2 crystal habit.
• Identified key deposition parameters, particularly temperature, for stabilizing P21/c and C2/m monoclinic VO2 structures.
• Confirmed compositional purity, controlled morphology, and thickness of VO2 films.
• Validated high-frequency functional properties of the synthesized VO2 films using THz spectroscopy.

Conclusions:

• MOCVD is a viable technique for precisely controlling VO2 thin film structure and morphology.
• Optimized MOCVD parameters enable the stabilization of desired monoclinic VO2 phases for THz applications.
• The synthesized VO2 films possess validated functional properties suitable for THz devices and sensors.