Crystallization Behavior of Solution-Processed CIGSe Thin Film Semiconductor by Stepwise Annealing Process

Area of Science:

• Materials Science
• Solid-State Chemistry
• Photovoltaics

Background:

• Copper Indium Gallium Diselenide (CIGS) thin films are crucial for photovoltaic applications.
• Controlling the synthesis process is key to optimizing CIGS film properties and device performance.

Purpose of the Study:

• To investigate the impact of selenization temperature on the formation and microstructure of CIGS thin films.
• To understand the role of intermediate phases during precursor selenization.
• To correlate film characteristics with photoelectron conversion efficiency.

Main Methods:

• Solution-based synthesis of Copper Indium Gallium (CIG) precursor films.
• Two-step selenization process with controlled temperature profiles.
• Analysis of intermediate phase formation and its effect on final CIGS structure.
• Characterization of polycrystalline structure and grain growth.
• Fabrication and efficiency testing of CIGS-based devices.

Main Results:

• Selenization temperature significantly influences the formation of intermediate phases (e.g., Cu, Se, CuSe, InSe, CuInSe2).
• The nature of these intermediate phases directly impacts the final CIGS film's polycrystalline structure and grain growth.
• Optimized selenization conditions led to CIGS films with photoelectron conversion efficiencies ranging from 1.59% to 2.75%.

Conclusions:

• The selenization temperature is a critical parameter for controlling CIGS thin film formation and microstructure.
• Understanding and controlling intermediate phase evolution is essential for achieving desired CIGS film properties.
• The solution-based precursor selenization method offers a viable route for CIGS thin film fabrication with moderate photovoltaic efficiencies.