Towards the Record Efficiency of Si Based Solar Cells

High-efficiency back-contact heterojunction crystalline Si (c-Si) solar cell with a record-breaking conversion efficiency of 26.7% is reported. The importance of thin-film Si solar cell technology for heterojunction c-Si solar cells with amorphous Si passivation layers in improving conversion efficiency and reducing production cost is demonstrated. Owing to the recent improvement of c-Si solar cells and perovskite solar cells, conversion efficiencies over 30% have become a realistic target by using a two-terminal tandem structure with a heterojunction c-Si solar cell and a perovskite solar cell.