Comprehensive study of rapid thermal firing for industrial production of crystalline silicon thick-film solar cells

Rapid Thermal Firing (RTF) of mc-Si thick-film solar cells is frequently considered as a promising alternative to contact firing in conveyor belt furnaces. Based on a fundamental process development yielding outstanding fill factors of up to 80.2 % on mc-Si (Baysix) material, RTF and state-of-the-art conveyor belt firing (CBF) have been thoroughly compared resulting at least in an as high efficiency potential of RTF as for state-of-theart CBF. IQE analysis of 7 Îcm Cz-Si solar cells revealed a similar Al-BSF quality for both techniques. While RTF did not change the minority carrier lifetime of cast mc-Si materials significantly, EFG Si solar cells clearly benefit from the improved hydrogen passivation of defects during RTF resulting in a considerable Voc and Jsc enhancement of 4 mV and 0.5 mA/cm2, respectively. Finally, based on the optimised process design a concept of an in-line and quasi-continuous RTF furnace for industrial high-throughput production has been developed.