Characterization and measurement of silicon solar cells with floating junction passivation

Theoretical and experimental demonstrations have shown that excellent rear surface passivation can be attained by using a floating junction. The extent to which the rear is passivated, however, can be difficult to ascertain, particularly when there exist parasitic shunts across the floating junction. This paper presents a new experimental technique suitable for bifacial floating junction solar cells, that determines two key parameters associated with the rear: the fraction of current transferred from the rear to the front, and the magnitude of the parasitic shunt resistance. In the latter case, either a local or a averaged value can be found. Measurements on floating junction buried contact solar cells show that the shunt resistance in buried contact solar cells can be over 1 MΩ.