Solar cells micro crack detection technique using state-of-the-art electroluminescence imaging

In this article, we present the development of a novel technique that is used to enhance the detection of micro cracks in solar cells. Initially, the output image of a conventional electroluminescence (EL) system is determined and reprocessed using the binary and discreet Fourier transform (DFT) image processing models. The binary image is used to enhance the detection of the cracks size, position and orientation, principally using the geometric properties of the EL image. On the other hand, the DFT has been used to analyse the EL image in a two-dimensional spectrum. The output image of the DFT consists of structures of all required frequencies, thus improving the detection of possible cracks present in the solar cell. As a result, the developed technique improves the detection of micro cracks in solar cells compared to conventional EL output images.