Thin-film solar panel manufacturing processes directly impact efficiency through material selection, deposition techniques, and structural design. Here’s how key steps influence performance:
1. Material Deposition Techniques
The method of applying photovoltaic layers (e.g., close-spaced sublimation for CdTe, PECVD for silicon) determines grain structure and defect density. High-quality microcrystalline silicon (µc-Si) in tandem-junction panels requires precise plasma-enhanced chemical vapor deposition (PECVD) to minimize defects and enhance light absorption. Poor deposition control can lead to inefficient charge carrier separation.
2. Layer Thickness and Bandgap Engineering
Thin-film panels use layers just nanometers to microns thick. Tandem-junction designs stack amorphous silicon (a-Si) for visible light absorption and µc-Si for infrared capture, optimizing the bandgap to cover more solar spectrum wavelengths. However, insufficient thickness or improper doping reduces photon absorption and carrier collection.
3. Laser Patterning and Interconnects
Laser scribing creates interconnected cell strips, but imprecise alignment increases electrical resistance. Overlapping scribes or poor spacing reduce active area and create “dead zones,” lowering overall module efficiency. Advanced laser systems minimize these losses in high-end production lines.
4. Substrate and Light Trapping
Textured TCO (transparent conductive oxide) coatings on glass substrates scatter light to prolong its path within the absorber layer, improving absorption. Manufacturing defects in TCO texture or thickness reduce light-trapping effectiveness, directly lowering current generation.
5. Encapsulation and Durability
Lamination processes must prevent moisture ingress and UV degradation. Poor sealing accelerates efficiency loss from corrosion or delamination, especially critical in flexible panels using plastic substrates. High-quality encapsulation materials extend operational lifespan but add cost.
| Manufacturing Step | Efficiency Impact |
|---|---|
| Deposition Quality | Determines charge carrier mobility and defect density |
| Layer Stack Design | Affects spectral absorption range (e.g., tandem vs. single-junction) |
| Laser Scribing | Influences resistive losses and active area coverage |
| Substrate Preparation | Controls light-trapping and reflection properties |
| Encapsulation | Mitigates environmental degradation over time |
Lower efficiency compared to crystalline silicon largely stems from intrinsic manufacturing constraints: thinner active layers reduce material use but limit photon absorption, while deposition scalability trades off against defect control. Advances in multi-junction designs and improved PECVD systems aim to bridge this gap.
Original article by NenPower, If reposted, please credit the source: https://nenpower.com/blog/how-does-the-manufacturing-process-of-thin-film-solar-panels-affect-their-efficiency/
