Stability of Dye Solar Cells with Photoelectrode on Metal Substrates

Abstract

In this study the stability of dye solar cells with different kinds of metals as the photoelectrode substrate is studied. Stainless steels, Inconel and titanium substrates were tested in order to find stable substrate options. Photovoltaic characterization, electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM) and substrate polarization measurements were used in the characterization.

Stabilization of metal counter electrodes for dye solar cells

“…Although, it is necessary for a substrate to pass the electrolyte soaking test, it does not guarantee the stability of the substrate in working conditions. In fact in our previous studies, we have detected stability problems when using StS as a photoelectrode [9,10] and as a counter electrode (CE) [11] substrate in DSCs. Interestingly enough, the degradation pattern and apparently also the causes for the degradation are different in those two cases [9][10][11].…”

“…In fact in our previous studies, we have detected stability problems when using StS as a photoelectrode [9,10] and as a counter electrode (CE) [11] substrate in DSCs. Interestingly enough, the degradation pattern and apparently also the causes for the degradation are different in those two cases [9][10][11]. The variation in the degradation is apparently caused by the different potential difference between the electrolyte and the electrode in the case of the two electrodes.…”

“…The DSCs with CE based on StS 304 have been stable for a couple of weeks in light soaking tests, but have then suffered from degradation [11]. The degradation of StS CE cells was apparently caused by corrosion as all the typical corrosion marks could be seen at the surface [11]: Iodine typically reacts with 4 the metal in the case of corrosion which causes then depletion of iodine in the electrolyte [4,5,8,11].…”

Low Cost Ferritic Stainless Steel in Dye Sensitized Solar Cells with Cobalt Complex Electrolyte

“…on the other electrode). [4][5][6] Here, the SEM images did not reveal any marks of corrosion in the surface of the aged ferritic steel as the example in Figure 7 shows. Furthermore, the elemental analysis combined to SEM imaging did not show any apparent corrosion products at the other electrode (i.e.…”

“…yellow redox couple 2,3,5,7,8 and/or results in a non-transparent corrosion product (typically very dark) that can be dispersed in the electrolyte or accumulated on the surfaces. 5,12 In the literature in the case of iodine electrolyte, the visual change of the electrolyte colour has actually been so clear that it has been used for tracking the progression of corrosion. 7 The cobalt electrolyte has a much more pale color compared to iodine electrolyte which makes the tracking of corrosion electrolyte color more difficult.…”