Reverse bias degradation in dye solar cells

A prolonged reverse bias (RB) stress forcing a short-circuit current through a dye solar cell, corresponding to the harshest test a shadowed cell may experience in real conditions, can cause the RB operating voltage V-RB to drift with time, initially slowly but accelerating for V-RB<(-1.65 +/- 0.15)V when gas bubbles, identified as H-2 (gas chromatography), are produced inside the cell, leading to breakdown. A close connection between VRB, cell performance, and stability was established. Contributions to RB degradation include triiodide depletion and impurities, in particular water. Acting upon these components and setting up protection strategies is important for delivering long-lasting modules. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4754116]