Doping‐Engineered Transition Metal Oxides: A Dual Strategy of Oxygen Vacancy Suppression and Photoelectric Modification for Silicon Compounds Heterojunction Solar Cells

ABSTRACT Replacing heavily doped silicon layers with wide‐bandgap transition metal oxides (TMOs) in crystalline silicon (c‐Si) solar cells shows great potential for reducing parasitic absorption, simplifying the fabrication process, and improving power conversion efficiency (PCE). However, the formation and migration of oxygen vacancies (V O ) and the limited tunability of optoelectronic properties in TMOs films hinder further performance gains. Combining first‐principles calculations with device simulation, this study explores how incorporating H, F, Cl, and Br into TMOs modulates their optoelectronic behavior, as well as their effect on dipole polarization at c‐Si/TMO interface. These dopants can effectively inhibit V O formation and migration, maintaining high work function (WF) and enabling tailored optoelectronic properties. Among them, H doping notably enhances the optical‐electrical properties and strengthens interfacial dipole polarization, leading to a PCE of 24.4%. Meanwhile, experimentally fabricated H‐doped TMO device exhibits an obvious efficiency enhancement relative to V O ‐TMO device, consistent with the theoretical results. This work bridges theoretical understanding and device realization, offering valuable guidance for designing high‐efficiency, dopant‐engineered c‐Si photovoltaics.