COMPARISON OF BIFACIAL AND MONOFACIAL LARGE-AREA n-TYPE SI SOLAR CELLS FROM 100 μm THIN WIRE-SAWN WAFERS

Reducing wafer thickness provides the most effective potential to lower the production cost of c-Si PV modules. Two thin n-type solar cell concepts are compared in terms of their optical and electrical properties: a monofacial device with a full-area metal surface at the rear which is beneficial in particular to such thin solar cells and a very similar but even better industrially applicable bifacially collecting device. The monofacial solar cell exhibits a 0.7 mA/cm higher jSC and 9 mV greater VOC due to better light trapping and less recombination. Rseries and FF discrepancies of both solar cell concepts nearly compensate themselves which is revealed by an Rseries itemization and FF loss analysis. The independently certified 20.1% efficiency of the monofacial solar cell exceeds that of the bifacial rear junction device by 0.7%abs under one-sided illumination. However, since the bifacial solar cells feature a very high bifaciality of 99.4%, a total power output comparable to a 23.4% efficient monofacial solar cell can be achieved assuming a typical albedo of 20%.