Highly improved passivation of PECVD p-type TOPCon by suppressing plasma-oxidation ion-bombardment-induced damages

•Two-step oxidation (TSO) was effective in suppressing the ion-bombardment damage.•PECVD p-TOPCon with TSO SiOx shows excellent passivation with an iVoc of ∼712 mV and a J0,s of ∼10 fA/cm2.•P-TOPCon with TSO SiOx produces a low contact resistivity of ∼10 mΩ·cm2.•An efficiency of 24.6% based on the state-of-the-art technology is predicted by numerical simulations.