Abstract
An algorithm which extracts the substrate-resistance-free current-voltage (J-V) characteristics from large-area solar cells is proposed here. The effect of substrate resistance on device performance was also discussed. We apply the algorithm to a set of real data measured from the devices with various device areas. The extracted results are matched with the real data. Besides, the extracted results of all devices are almost identical. Both observations cement the validity of the proposed algorithm. The dependence of device performance and circuit-level parameters on the device length can be analyzed with this algorithm. Negative dependence of the power conversion efficiency (PCE), the short-circuit current (Jsc) and the fill factor (FF) of devices on the device length is observed while the open-circuit voltage (Voc) shows no dependence on the device length. This observed effect can be explained by the non-uniform potential distribution on the substrate. Finally, we used the algorithm to quantify the effect of the substrate resistance and short-circuit current on device performance. We found that increases in percentage change of PCE, Jsc, FF, Rs and Rsh as sheet resistance of substrate or short-circuit current increase. The percentage change of FF is the maximum value, so we can conclude that substrate resistance affects FF most.