Study on inspection of degeneration of solar cells with optical coherence tomography

• Main Authors: Chia Chu Wang, 王佳筑
• Other Authors: M. T. Tsai
• Format: Others
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/71799278406027652858

碩士 === 長庚大學 === 電機工程學系 === 103 === A solar cell can directly convert sunlight or artificial light into electricity, producing both a current and a voltage to turn out electrical power. However, the conversion efficiency of solar cell could be influenced by the quality and environment of solar cells. Therefore, the inspection and measurement of solar cells has become an important technique in evaluating the efficiency and quality of solar cell devices. In this study, we propose the use of optical coherence tomography (OCT) for the inspection of solar cells. OCT has the advantages of non-invasive, depth-resolved and high-speed imaging without the destruction of samples. OCT can reconstruct the two-dimensional or three-dimensional microstructures with the resolution in micrometer scale, enabling the measurable imaging depth to achieve 3 mm below the sample surface. To investigate the morphological change after the aging tests including temperature and moisture, solar cells were scanned with OCT. From the results, one can see that the interface between silicon layer and Al conducting plane became disconnected, resulting in the reduction of conversion efficiency. In addition, from the results of the moisture aging test, the gel to connect the electrodes and silicon was melt, causing the gel released and accumulated around the electrodes.