Surface Pb-Dimer Passivated by Molecule Oxygen Notably Suppresses Charge Recombination in CsPbBr3 Perovskites: Time-Domain Ab Initio Analysis

, occurring on tens of picoseconds. Pb-dimer passivated with oxygen molecules forms Pb-O bonds, breaks the Pb-dimer, and removes the trap state, leading to a decrease in the recombination and extending excited-state lifetime to over 100 ps. The deceleration arises mainly due to the reduced NA coupling and short decoherence time. The study advances our understanding of excited-state dynamics of all-inorganic perovskites in the presence of excess lead and oxygen atmosphere.