Figure 2
Long-term one-sun illumination of a POLO BJ solar cell on Ga-doped Cz-Si at 80 °C for 1400 h. Shown are the measured parameters (a) energy conversion efficiency η, (b) open-circuit voltage VOC, (c) fill factor FF together with the pseudo fill factor pFF, and (d) short-circuit current density JSC versus the illumination time t (open circles). In addition, the initial values measured directly after contact firing are shown (closed symbols). Before the experiment starts, the solar cell is illuminated at 0.5 suns for 15 min, increasing the efficiency from its initial value (slightly below 22%) to 22.1%.
