Extraction of Five Photovoltaic Parameters of Nature-based Dye-Sensitized Solar Cells using Single Diode Model

Dye-Sensitized solar cells (DSSCs) are among the family of third generation photovoltaic (PV). DSSCs are promising with the theoretical predicted value for power conversion efficiency (PCE) of 20%. In this paper, explicit equations for the single-diode equivalent circuit model parameters of a solar cell were modeled based on the characteristic points on the I-V curves that do not require the short-circuit and open-circuit slopes as input data. The equations were used to calculate the five model parameters (n, Rs, Rsh, Iph, Io) of a standard solar cell-based DSSCs composed of different natural photosensitizers. The results show that four(~28.5%) devices with natural photosensitizers (bitter gourd, sun flower, rose flower, tomato) manifest parameter irregularities i.e. they have negative series resistance or complex shunt resistance. Despite the occurrence of irregular parameters, there is still a good match between the calculated and measured photoelectric characteristics. This supports the idea that the nature of the parameter values does not matter provided there is a good match between measured and calculated I-V characteristics. The bitter gourd-based DSSC demonstrates the most promising photosensitizer for DSSC fabrication based on values of the parameters. Hence, the agreement of the calculated and measured parmeters suggests that modeling is good approach for extraction solar parameters.