Large‐area MoOx/c‐Si heterojunction solar cells with a ICO/Ag back reflector

Abstract Compound/silicon heterojunction (SCH) solar cells have been widely studied because of the low parasitic absorption of the window layer, high short‐circuit current, and simple preparation process. So far, most reported SCH solar cells are small‐area devices. By depositing MoO x hole transport layer using hot‐wire oxidation–sublimation deposition technique and employing a front‐contact back‐junction cell architecture, the large‐area SCH solar cells are successfully fabricated on M6 (166 mm) n‐type silicon wafers. Indium cerium oxide (ICO) film with the optimal thickness of about 110 nm is inserted between MoO x and Ag. The ICO/Ag stack functions well as a back reflector and is beneficial for increasing the short‐circuit current density, reducing the contact resistance, and improving the device stability. A power conversion efficiency of 21.59% is achieved on the champion SCH solar cell with the device area of 274.15 cm 2 .