Efficient Silicon Solar Cells with Aluminum‐Doped Zinc Oxide‐Based Passivating Contact

Abstract Crystalline silicon ( c ‐Si) solar cells require passivating contacts to unlock their full efficiency potential. For this doped silicon layers are the materials of choice, as they yield device voltages close to the thermodynamic limit. Yet, replacing such layers with wide‐bandgap metal oxides may be advantageous from a cost perspective and minimize parasitic optical absorption. Here the aluminum‐doped zinc oxide (AZO)‐based passivating contacts with high electron selectivity are presented. The SiO 2 /AZO/Al 2 O 3 stack is demonstrated to provide excellent surface passivation on c ‐Si (implied V oc up to 742 mV) after thermal annealing, and an average contact resistivity of 51 mΩ cm 2 is simultaneously obtained after etching off Al 2 O 3 capping layer. By the implementation of AZO‐based electron‐selective contact, a champion power conversion efficiency (PCE) of 24.3% is achieved on c ‐Si solar cells, representing the PCE record for metal oxide‐based passivating contacts. Finally, the efficiency potential, cost, and industrial compatibility of the AZO‐based electron‐selective contacts are discussed, paving the way for industrial applications.