To investigate the role of the carrier mobilities on the performance parameters of BHJ blend with thickness of 80 nm, the solar cell parameters are shown as a function of electron and hole mobility in the Fig.6 (a-d). As can be seen, the high performance happens when electron and hole’s mobility are high. However, when the mobilities surpasses a certain value, the performance gets approximately constant. The short circuit current, Jsc, increases with the mobility until the saturation is reached at balanced mobilites about 10-6 m2/V.s.
The open circuit voltage, Voc, as well as the fill factor, FF, in Fig. 6(b) and 6(c), show an increasing behavior with mobility and stay almost constant at higher mobilities. The integration of the behavior of the mentioned parameters leads to the efficient power conversion efficiency at balanced mobilities about 10-6 m2/V.s as shown in Fig.
6(d). It means that high carrier mobilities are not the only factor to maximize the device efficiency.