Doping-Engineered Transition Metal Oxides: A Dual Strategy of Oxygen Vacancy Suppression and Photoelectric...

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.