Current-voltage curve comparison

For the industrial screen-printed solar cell of Table 5.3, where the series resistance image was shown in Fig. 5.27, we first compare the calculated and measured global IV curves.


Figure 5.31A shows the measured global IVcurve (green circles) and the calculated curve using the two-diode model (solid line). For this calculation, the parameters as given in Table 5.3 are used. The parameters J01, J02, and Rsh were determined with a least-square regression of the two-diode model to the measured data of the Jsc-Voc characteristics, the series resistance Rser, FF followed from the light-IV and Jsc – Voc characteristics and Jsc directly from the measured light-IV characteristics. This comparison of the simulated to the measured light-IVcharacteristic demonstrates that the global two-diode model does not describe well this solar cell.

Figure 5.31 Measured global IV data (green circles) of the industrial screen-printed solar cell of Table 5.3 and Figure 5.27 compared to calculation with the global two-diode model (A) and to the LIA approach (B).

Figure 5.31B shows the measured global IVcurve (green circles) and the calculated curve obtained from the LIA approach using a measured series resistance image. Both curves are in good agreement. For this solar cell, the LIA approach results in a more realistic IV characteristic than the two-diode model, shown in Fig. 5.31A. As a result of the LIA approach, an efficiency of 16.18% is obtained, which is in good agreement to the mea­sured value of 16.04%. Virtual data manipulation

We now virtually manipulate the series resistance image to the best local value of 0.7 O cm, as shown in Fig. 5.32. This new series resistance image is fed into the LIA approach again. The resulting new global energy conver­sion efficiency predicts a total power improvement by this manipulation of 0.27 mW/cm2.

Updated: July 1, 2015 — 7:41 am