Production process control is considered a key success factor for the solar industry. However, this is only part of the favorable conditions for success: In order to fully optimize production and reduce costs, producers must take further steps to ensure that only defect-free materials are processed.

In order to effectively avoid the waste of consumables and the waste of time for defective products, it is necessary to conduct a comprehensive online inspection of the characteristics of each relevant silicon wafer. The new generation of non-contact photoluminescence detection system (PL detector) provides high-precision and high-speed quality assurance for solar silicon wafers. With its advanced technical features, the system can accurately predict cell efficiency based on raw silicon wafer analysis. By investing only in well-processed silicon wafers, the operator has significantly reduced production costs.

The system uses photoluminescence technology. In contrast to electroluminescent systems, detection and efficiency measurements are made contactless. This avoids cracks, breakages and other common defects caused by electronic contacts. This innovative solution offers the best performance for defect detection and classification thanks to photoluminescence-based homogeneous illumination of the complete area (up to a range of 170mmx170mm). The system reliably identifies a wide range of defects including crystal defects, edge impurities and background contamination. Special image filtering technology can automatically identify critical and non-critical defects. Compared with the traditional photoluminescence method, the development time is shortened to one-eighth. In addition, no specialized silicon wafer positioning is required. In this way, more than 3,600 wafers can be inspected per hour.