Trace Impurity Tolerance of Polymer Solar Cells

Organic bulk heterojunction photovoltaic solar cells (OPV), with record efficiency approaching 19% and proven high stability, are becoming a credible technology to participate in the global renewable energy bouquet. In this context, OPV manufacturers need materials in sufficient quantity and certified quality. Batch-to-batch variations must be eliminated and impurities content should be carefully controlled, could them be organic or metallic traces. This presentation will show a panorama of what is known, to date, concerning the effects of impurities in the raw semiconductor on solar cells. Our recent research will be presented describing our strategies to identify critical impurities and to estimate the tolerance threshold of solar cell. If initial post-fabrication efficiency of solar cells is obviously examined, our studies also explore the impurity effects on the stability of solar cells under illumination. Care is taken to understand the fundamental mechanisms associated with impurity effects.