CIGS Thin Film Characterization

The main area for potential improvement of CIGS thin film PV is performance reliability and uniformity as manufacturing is scaled up. Materials characterization using surface analytical methods provided by EAG are used to support R&D for efficiency improvements and also production ramps.

All the major layers can be characterized with EAG analytical techniques, leading to improved knowledge of the samples and hence the ability to relate the characterization information to efficiency measurements and also production and process conditions

The following components are commonly analyzed:

1. Substrate (e.g. glass. metal, polymer) and metal coating (e.g. Mo)

Mo thickness: XRR

Mo microstructure: XRD (for phase ID), SEM, AFM

Porosity: TEM

Oxygen content in Mo: XPS, RBS

Na content: SIMS (can be done through the entire structure)

Substrate defects: AFM, AES

2. CIGS layer

Grain morphology and voids: SEM, TEM

Grain composition: STEM/EDS, AES

Film composition: SIMS, AES

Impurities and Na content: SIMS

Phase ID: XRD

Surface stoichiometry: XPS

3. Upper Layers (CdS, ZnO, TCO)

Thickness and composition: XRR, RBS

Phase: XRD

4. Failure analysis for organic components (all layers)

FTIR, GCMS, XPS, Raman, or TOF-SIMS.

5. Starting materials purity

GDMS, ICP-MS, ICP-OES.

Further information is available here.