Understanding the Influence of Shunts in the I-V Curves and Electroluminescence of Multijunction Solar Cells

The influence of shunts on multijunction solar cells cannot be directly extrapolated from their effect on single junction solar cells. It is shown that the rules of thumb for single junction solar cells can mislead to wrong diagnosis on multijunction solar cells when they are only partially shunted. In order to properly assess their performance, three dimensional simulations have been carried out using equivalent electrical circuits. In this work, we point out the differences between completely and partially shunted multijunction solar cells under different regimes and evaluate the use of I V curves and electroluminescence as valid tools to detect the existence of shunts. A straightforward application of this work is its use in reliability analysis, allowing an undoubtedly identification of shunts at both the solar cell manufacture and on-field operation