Investigating the Effect of Shading Mask Aperture Area on I-V Curve Characterization of Nanostructured Photoanode of Dye-Sensitized Solar Cells

I-V curve measurement under illumination has been extensively employed for the photovoltaic characterization of dye-sensitized solar cells (DSSCs) in last three decades. Usually, a shading mask with an aperture is used to prevent the overestimation of short-circuit current density (I-sc) due to an edge effect. A recent investigation showed that using a shading mask, however, leads to underestimation of open circuit voltage (V-oc) and overestimation of fill factor (FF) in planar perovskite solar cells. In the present work, the effect of shading mask aperture size on photovoltaic parameters was investigated in DSSCs. The obtained results confirmed Kiermasch's observations. It was observed that I-sc is independent of the shading mask aperture size. Utilizing a shading mask with a smaller aperture size compared to the DSSC active area decreased V-oc, but increased FF. As a result, smaller aperture size led to higher power conversion efficiency. Although using a small aperture shading mask for characterization of DSSC gives the correct I-sc, it leads to erroneous determination of V-oc and I-sc.