Imaging of shunts and junction breakdown in multicrystalline silicon solar cells

Recently, there has been a great deal of work investigating shunting defects in silicon solar cells. With the advancements in such techniques as DLIT, EL, and PL, shunting behavior can now be correlated to specific locations and specific defects. Shunts, which decrease device performance, are revealed under a reverse applied bias. Many of these shunts also generate a photonic emission under reverse bias, which can be observed with visible and near-IR spectrum detectors. This photonic emission or radiative recombination is often referred to as a visible breakdown emission. We investigate if each type of impurity or crystallographic defect has a unique emission spectra that can be used to identify it.