Electron‐Selective Contacts ATO/LiF/Al‐Based High‐Performance N‐Type Silicon Solar Cells

Abstract Due to its excellent passivation and low contact resistivity, Al‐doped TiO 2 (ATO) has become one of the most promising candidates for dopant‐free carriers‐selective contacts (CSCs). This work prepares the ATO/LiF/Al electron‐selective contacts and applies them to the n‐type silicon solar cells as full‐area rear CSCs. It is found that 6 nm‐thickness ATO thin film possesses the highest minority carrier lifetime of 253.0 µs on solar‐grade Cz n‐type wafers, revealing the ultra‐low saturated current density J 0 of 120.7 fA cm −2 . Meanwhile, the 6 nm‐ATO/LiF/Al electron‐selective contact has a significantly low contact resistivity ρ c of 19.7 mΩ cm 2 , suggesting a sound electronic transport property of the ATO/LiF/Al stack. Finally, a highest solar cell efficiency of 19.9% is obtained for an n‐type crystalline silicon device with a full‐area rear ATO/LiF/Al contact. The calculated selectivity S 10 of 13.0 enables the maximum efficiency of 27.3% for the ATO/LiF/Al‐based n‐type solar cell, demonstrating the great potential of applying this passivating contact in high‐efficiency silicon solar cells.