KY Goon, Executive Chairman – TTVision | Topic: Transflection Imaging for Solar Cell Micro-Crack Detection
Existing methods such as electroluminescence and photoluminescence are used today to detect micro-cracks in solar cells as such defect are invisible to naked human eyes. However, these tools produce noisy images which are often indistinguishable to micro-cracks. Resolving this issue has led to a design of an imaging system based on light transflection principle. In this case, a light enters a solar cell and is diffusely scattered in multiple directions. As a result, an area in the vicinity of the incident light is illuminated from beneath the surface. The presence of micro-cracks along the transmission path of the transflected light causes an abrupt change in the illumination intensity, thereby creating a representation of the defect. This transmission of light however is not influenced by grain boundaries, dislocations, cosmetic scratches, etc. Therefore such images are much clearer and can be more reliably processed with less chances of misclassification.