Isotype bifacial silicon solar cells obtained by ITO spray pyrolysis

In this work we realized a new kind of bifacial solar cell with two isotype junctions based on the semiconductor–insulator–semiconductor structure. These devices were fabricated on nSi Cz wafers; the front junction was realized depositing ITO using the spray pyrolysis technique. A back surface field region was obtained by a P-diffusion process at the rear contact. To better evaluate the effectiveness of the rear side, we compared the performances of the latter cell with monofacial one having the same front junction, but with an extended metal contact on the rear surface of the wafer. All the devices were characterized by IV light, IV dark and quantum yield. The best bifacial cell realized in our laboratory achieved the efficiency of 9.0% (front side illumination) and 3.6% (rear side illumination), while the efficiency for the best monofacial solar cell was 9.6%.