-"Luminoscopy"-Novel Tool for the Diagnosis of Crystalline Silicon solar cells and Modules Utilizing Electroluminescence

We propose a novel technique of "Luminoscopy" in which the deficiencies in the cells and modules can be clearly detected by photographic surveying of electroluminescence (EL) without any probing tools. Under the forward bias condition, the cell emits infrared light (lambda=1100 to 1200 nm), whose intensity reflects the number of minority carriers in p-type layer. The EL intensity distribution clearly agreed with map of L in poly-Si. This technique has another attractive feature. The crack and defect show low EL intensity. This work was focused on the inspection of silicon solar cells. Cracks or defects in cell or modules were detected within very short time less than 1s at room temperature. This result demonstrates that "Luminoscopy" have the potential for in-line inspection in production