A comparative study on alternative industrial manufacturing routes for bifacial n‐PERT silicon solar cells

Abstract

Bifacial n‐PERT solar cells, taking advantage of the superior material quality of n‐type Si wafers and the high bifaciality potential of the design, can be fabricated by the existing industrial manufacturing methods. Here, we compare five alternative process flows to manufacture the bifacial n‐PERT solar cells. The complexities of their fabrication routes vary mainly according to the applied doping methods (either diffusion or ion implantation) and the rear side morphology (either alkaline textured or hardly etched pyramidal surface). We also analyze the performance of the devices fabricated by each process flow. Our results indicate that the solar cells with a B‐diffused emitter and P‐implanted BSF yield higher efficiencies than the others. In addition, the n‐PERT solar cells with hardly etched pyramidal rear surfaces have slightly higher efficiency than those with textured rear surfaces. Moreover, we studied the responses of the n‐PERT solar cells against the degradation and regeneration processes applied to boron‐doped p‐type Si solar cells under dark annealing, light soaking, and illuminated annealing. They are not significantly influenced by light‐induced degradation (LID); however, the fill factor (FF) value of the cell with hardly etched pyramidal rear surfaces is sensitive to the illuminated annealing process.