Evaluation and Assessment of the ASPIRE Concept: A New Integrated mc-Si Cell and Module Design for High-Efficiencies
The majority of commercial crystalline Si cell production is carried out on p-type crystalline silicon using an H-patterned cell concept with full aluminum rear surface. To decrease the Euro/Watt-peak price, higher efficiencies have to be reached while using less material. In this paper, the ASPIRe cell concept is put forward as a candidate to further these goals. In the ASPIRe cell two technologies are combined: 1) Metal wrap through technology; reducing the front metal coverage and moving all
... rage and moving all contacts to the rear, and 2) dielectric rear side passivation; reducing the bow for thinner wafers, increasing the rear passivation and reflection, and reducing the metal consumption due to rear grid instead of full area aluminum. To evaluate the ASPIRe concept, ASPIRe cells have been modeled using 2D simulation methods. Depending on the resistivity of the rear side metallization, and on the full area BSF quality, a relative efficiency gain of 2 to 4% was calculated for ASPIRe cells compared to full aluminum rear MWT cells. Using industrially applied Al2O3 as rear passivating layer and optimized rear metallization patterns, ASPIRe cells with higher Jsc*Voc and FFs close to their full Al references were be made. One final bottleneck for the industrialization of the ASPIRe concept is a cost effective way to form of a good local BSF below the metal lines. Cost and environmental calculations show that, once this is solved, the ASPIRe concept indeed enables lower Euro/Watt-peak and shorter energy-payback-times than the standard cell concept.