Cerium-Doped ZnO Thin Films for Photocatalysts

Area of Science:

• Materials Science
• Nanotechnology
• Photocatalysis

Background:

• Zinc oxide (ZnO) is a versatile semiconductor with applications in optoelectronics and environmental remediation.
• Controlling the properties of ZnO thin films is crucial for optimizing their performance.
• Cerium (Ce) doping is explored as a method to tune ZnO's characteristics.

Purpose of the Study:

• To investigate the impact of varying cerium (Ce) concentrations on the optical, structural, morphological, and photocatalytic properties of ZnO thin films.
• To determine the optimal Ce doping level for enhanced photocatalytic activity.
• To assess the potential of Ce-doped ZnO for environmental applications.

Main Methods:

• Thin films of pure and Ce-doped ZnO were fabricated using thermal vacuum evaporation.
• Characterization techniques included Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD), Atomic Force Microscopy (AFM), UV-VIS spectroscopy, and ellipsometry.
• Photocatalytic activity was evaluated to assess degradation efficiency.

Main Results:

• All films maintained the hexagonal wurtzite structure, with Ce incorporation causing lattice strain and reduced crystallite size.
• 2% Ce doping resulted in smaller grain size and lower surface roughness compared to 5% doping.
• Ce doping induced a red shift in the absorption edge, narrowed the optical band gap, and improved charge carrier separation, with 2% Ce-doped ZnO showing the highest photocatalytic efficiency.

Conclusions:

• Controlled cerium doping is effective in tuning the microstructure, optical properties, and photocatalytic performance of ZnO thin films.
• The 2% Ce-doped ZnO film exhibits superior photocatalytic activity, attributed to improved charge carrier separation and increased oxygen vacancies.
• These findings suggest Ce-doped ZnO thin films are promising materials for environmental remediation and optoelectronic devices.