Solution based synthesis of Cu(In,Ga)Se₂ microcrystals and thin films

Area of Science:

• Materials Science
• Nanotechnology
• Renewable Energy

Background:

• Quaternary semiconductor materials are crucial for thin-film solar cell applications.
• Developing cost-effective synthesis methods for high-performance absorber layers is essential.

Purpose of the Study:

• To report the first synthesis of quaternary Cu(In,Ga)Se2 microcrystals (CIGSe MCs).
• To investigate the influence of reaction parameters on CIGSe MC properties.
• To evaluate the potential of CIGSe MCs in thin-film solar cells.

Main Methods:

• One-pot heating-up synthesis of CIGSe MCs.
• Variation of reaction temperature and time to optimize properties.
• Drop casting of CIGSe MCs for thin-film fabrication.
• Characterization of structural, morphological, compositional, and optical properties.

Main Results:

• Successful synthesis of pure phase CIGSe MCs with controllable size and band gap (1.10–1.28 eV).
• High reaction yield (90%) achieved for large-scale synthesis.
• CIGSe MC thin films exhibit optimal carrier concentration, high mobility, and low resistivity.
• Photoconductivity enhanced by three orders of magnitude compared to CIGSe nanoparticles (NCs).

Conclusions:

• CIGSe MCs demonstrate superior performance over CIGSe NCs in solar cell applications.
• Fabricated solar cells using CIGSe MCs achieved a power conversion efficiency (PCE) of 0.59%.
• CIGSe MCs show significant potential as an active absorber layer for low-cost thin-film solar cells.