Spectrally Selective Thermal Management ITO/Ag/ITO Multilayer Thin‐Film for Silicon Photovoltaics

Crystalline silicon (c‐Si) photovoltaics (PVs) are central to the global renewable energy transition due to their low cost, established manufacturing infrastructure, and proven outdoor durability. However, their power conversion efficiency (PCE) is hindered by parasitic optical reflection and thermalization losses that elevate device temperature and accelerate performance degradation. To address these limitations, this study introduces a multifunctional transparent oxide–metal–oxide (OMO) multilayer composed of indium tin oxide/silver/indium tin oxide (ITO/Ag/ITO) multilayer coating in which a thin Ag interlayer is sandwiched between metal oxide films to enhance ultraviolet (UV) light utilization while selectively reflecting infrared (IR) photons that contribute to parasitic heat generation, achieving spectrally selective optical management unachievable with single‐layer transparent conducting oxides (TCOs). OMO structures were fabricated via solid sputtering to be integrated onto commercial c‐Si solar cells. The optimized OMO layer shows a clear improvement in the fill factor (FF) compared to the c‐Si solar cell and maintains higher operational stability under prolonged illumination and high‐temperature conditions. Under full‐spectrum AM 1.5G illumination at 1000 Wm ⁻² , the initial PCE values of bare c‐Si, c‐Si/OMO‐A, and c‐Si/OMO‐B were 18.02%, 9.1%, and 9.6%, respectively. After 60 min of continuous illumination, the corresponding PCE retentions were 75.6%, 90.1%, and 96.9%. Under monochromatic UV light conditions, the optimized OMO structure device efficiency increased by 3.91% compared with that of the bare c‐Si cell. These results establish the ITO/Ag/ITO multilayer as a scalable and manufacturable solution for enhancing both efficiency and durability in commercial silicon PVs, thereby increasing the real‐world value of c‐Si technology in a carbon‐conscious, renewable‐energy‐driven future.