Charge-Transfer Induced by the Oxygen Vacancy Defects in the Ag/MoO₃ Composite System

Area of Science:

• Materials Science
• Nanotechnology
• Surface Chemistry

Background:

• Molybdenum trioxide (MoO3) possesses a wide band gap, limiting its applications.
• Oxygen vacancy defects in metal oxides can influence electronic properties and charge transfer.
• Surface-enhanced Raman scattering (SERS) is a sensitive technique for molecular detection.

Purpose of the Study:

• To investigate the role of oxygen vacancy defects in Ag/MoO3 composite systems.
• To evaluate the contribution of these defects to charge transfer and SERS enhancement.
• To explore the potential of oxygen-containing semiconductors for SERS applications.

Main Methods:

• Cosputtering of Ag/MoO3 composite on polystyrene (PS) colloidal microspheres using Ar plasma.
• Characterization of oxygen vacancy defects using various analytical techniques.
• SERS measurements using 4-aminothiophenol (PATP) as a probe molecule.

Main Results:

• Abundant oxygen vacancy defects were successfully introduced into the MoO3 component.
• These defects facilitated charge transfer within the Ag/MoO3 composite system.
• SERS spectra of PATP showed characteristic peak shifts, correlating with the density and utilization of oxygen vacancies.

Conclusions:

• Oxygen vacancy defects serve as crucial charge channels in Ag/MoO3 composites, significantly boosting SERS activity.
• The manipulation of charge channels offers a new pathway for optimizing SERS performance in oxygen-containing semiconductors.
• This research provides valuable insights for the study of PATP and the development of advanced SERS substrates.