Non-contact electroluminescence defect detection method

A non-contact electroluminescence defect detection method, comprising:

• irradiating a moving solar cell with a laser to obtain an irradiation area, and simultaneously acquiring a center photoluminescence image, and a left electroluminescence image and a right electroluminescence image based on the irradiation area;
• performing a fusion processing on the center photoluminescence image, the left electroluminescence image, and the right electroluminescence image to identify overlapping boundary regions, and conducting a shape analysis on the overlapping boundary regions to determine a boundary distortion, and locating initial defect position coordinates based on the boundary distortion;
• measuring a left diffusion distance and a right diffusion distance based on the left electroluminescence image, and the right electroluminescence image, generating a diffusion asymmetry degree based on the left diffusion distance and the right diffusion distance, and determining a defect shift direction based on the asymmetry degree, and correcting the initial defect position coordinates based on the defect shift direction to generate accurate defect position coordinates;
• extracting a center luminescence intensity from the center photoluminescence image, and extracting an edge luminescence intensity from the left electroluminescence image, and the right electroluminescence image, and forming a luminescence gradient curve based on the center luminescence intensity and the edge luminescence intensity, and identifying intensity jumping points through the luminescence gradient curve;
• adopting the intensity jumping points as dividing points to segment a luminescence response interval, establishing an energy distribution index based on the luminescence response interval, identifying energy conversion defects at the accurate defect position coordinates based on the energy distribution index;
• conducting a conduction path analysis based on the accurate defect position coordinates and the energy conversion defects to determine a defect coupling coefficient;
• identifying defect types based on the defect coupling coefficient, and outputting a spatial positioning map based on the defect types, completing the non-contact electroluminescence defect detection.