2D Characterization of OPV from Single and Tandem Cells to Fully Roll‐to‐Roll Processed Modules with and without Electrical Contact

A new type of light beam‐induced current 2D mapping system is developed that speeds up acquisition time from hours and days to minutes or even seconds. It is particularly relevant as a tool to characterize printed, large‐scale, organic photovoltaics. Defects inherent to the multi‐layer printing or degradation effects that develop later can be detected with a spatial resolution of <100 μm. It can be used as an in‐line characterization element in the roll‐to‐roll production of organic photovolatics. Several types of electrical connection schemes are developed, including methods suited for continuous web transport. One particularly exciting development is contactless connection through capacitive coupling, which is especially suited for fast roll‐to‐roll characterization of organic photovoltaic modules during the process where electrodes might not be accessible for making a physical electrical contact. Another variation of the technique allows for the extraction of solar cell parameters such as the capacitive time constant, capacitance, and shunt‐ and series resistance at every position (pixel) in the device, which allows new types of 2D mapping that bring out variations and defects in solar cells that are complementary to standard LBIC. It for instance becomes possible to distinguish a short from an open circuit.