Investigation of a CIGS solar cell with ARL EQUINOX 100 X-ray Diffractometer and ARL QUANT'X EDXRF Spectrometer

Significance of the Topic

Thin-film solar cells based on copper indium gallium selenide (CIGS) offer cost-efficient alternatives to conventional crystalline silicon modules due to minimal material usage. Reliable quality control and performance assessment of layered structures in CIGS devices are essential to optimize efficiency and manufacturing yield.

Objectives and Overview of the Article

This application note demonstrates a combined analytical approach employing a benchtop X-ray diffractometer and an energy dispersive X-ray fluorescence spectrometer for rapid structural and compositional analysis of CIGS solar cell layers in both research and industrial environments.

Methodology and Instrumentation

• X-ray diffraction: ARL EQUINOX 100 X-ray diffractometer with Cu Kα radiation and curved position sensitive detector for fast grazing incidence XRD scans at 1° and 5° angles, 2 minutes per scan.
• X-ray fluorescence: ARL QUANTX EDXRF spectrometer equipped with a Rh tube and silicon drift detector, operating up to 50 kV and 50 W, using fundamental parameters for concentration and thickness determination.
• Sample alignment and data processing: thin film attachment with motorized ω and Z control; SYMPHONIX and MDI JADE software with pdf4+ database for phase identification; WinTrace for EDXRF analysis.

Main Results and Discussion

Grazing incidence XRD selectively revealed the CIGS absorber phase at 1° and additionally the Mo back electrode peaks at 5°, demonstrating layer-specific crystallographic analysis within two minutes. EDXRF quantified the absorber layer (1.43 µm) composition as Cu 19.5%, Se 46.8%, In 23.5% and Ga 10.2%, and the Mo electrode layer (0.34 µm) as pure molybdenum. This dual approach enables comprehensive quality assessment of both structural and chemical properties.

Benefits and Practical Applications

• Rapid, real-time screening of thin-film solar cell samples.
• Low infrastructure demands and portable benchtop configuration.
• Straightforward sample alignment with minimal operator expertise.
• Integrated QC/QA workflow for layer thickness, composition and crystallinity.

Future Trends and Potential Applications

Emerging developments may include automated in situ monitoring during film deposition, integration with machine learning for predictive quality control, extension of combined XRD–EDXRF methods to other photovoltaic and coating materials, and deployment of portable analytical stations for on-site manufacturing verification.

Conclusion

The synergy of ARL EQUINOX 100 XRD and ARL QUANTX EDXRF offers a robust, rapid, and user-friendly protocol for characterizing CIGS solar cell layers. This integrated solution supports enhanced QC/QA practices and accelerates research and production workflows in thin-film photovoltaics.

References

• Thermo Fisher Scientific Inc. 2020. Investigation of a CIGS solar cell with ARL EQUINOX 100 X-ray Diffractometer and ARL QUANTX EDXRF Spectrometer. Application Note XR-AN41123.