20.7% highest efficiency large area (100.5 cm2) HITTM cell

A world record total area conversion efficiency of 20.7% and high open circuit voltage (VOC) of 719 mV were achieved on a solar cell with HIT (heterojunction with intrinsic thin-layer) structures on both sides (wafer size: 100.5 cm², n-type solar-grade CZ-Si). This solar cell was fabricated with the same process as that used in our mass-production lines. The essence of this high performance is derived from the excellent passivation ability of the HIT structure on c-Si. This report discusses research for excess of 20% efficiency HIT cell (~100 cm²), focusing on the a-Si passivation effect estimated from the carrier lifetime, and describes product development for the industrialization of HIT cells