• • CdO:Sm ICL achieves a contact resistivity of 1.68 mΩ cm2 (measured via Si/CdO:Sm/NiOx/Ag structure), ensuring low resistive losses critical for high fill factor in tandem devices.
• • The CdO:Sm film exhibits average transmittance of 85% (400–1200 nm) and 90% (800–1200 nm), maximizing near-infrared light utilization by the silicon bottom subcell, directly boosting current density.
• • Work function of CdO:Sm is 4.04 eV, significantly lower than IZO (4.64 eV), promoting efficient carrier tunneling and recombination at the ICL, as evidenced by enhanced VOC and FF.
• • Time-resolved photoluminescence shows faster carrier lifetimes (τ1=45.4 ns, τ2=376.1 ns) for CdO:Sm compared to IZO (τ1=47.8 ns, τ2=447.9 ns), indicating superior carrier extraction and reduced recombination losses.