26.6%-Efficiency Silicon Heterojunction Solar Cell with High-Quality Cerium and Hydrogen Codoped Indium Oxide Transparent Electrode

High-performance transparent conductive oxides (TCOs) with low electrical resistivity and high transparency are highly desirable for silicon heterojunction (SHJ) solar cells. Herein, high-quality cerium (Ce) and hydrogen codoped indium oxide (ICO:H) is prepared by reactive plasma deposition (RPD) and verified on SHJ solar cells. The effects of CeO₂ doping ratio, H₂/Ar ratio, and annealing treatment on the optoelectronic properties of ICO:H were investigated and optimized. We obtain high-performance ICO:H films with simultaneous state-of-the-art mobility of 169.2 cm²/(V s), low carrier concentration of 1.9 × 10²⁰ cm^–3, and high transparency. As a result, a certified power conversion efficiency (PCE) of 26.6% is achieved for SHJ solar cells with ICO:H, featuring less dependency on the underlying hydrogenated nanocrystalline silicon oxide (nc-SiO_x:H) layer. The implementation of ICO:H in an industrial production line demonstrates a higher PCE and better yield.