Spinor Dynamics in Pristine and Mn2+-Doped CsPbBr3 NC: Role of Spin–Orbit Coupling in Ground- and Excited-State Dynamics

Fully inorganic lead halide perovskite nanocrystals (NCs) are of interest for optoelectronic and light-emitting devices because of their photoluminescence (PL) emission properties, which can be tuned/optimized by (I) surface passivation and (II) doping. (I) Surface passivation of the NC affects PL capabilities, as an underpassivated surface can introduce trap states, which reduces PL quantum yields. (II) Doping NCs and quantum dots with transition-metal ions provides stable optical transitions. Doping perovskite NCs with Mn2+ ions provides high-intensity 4T1 → 6A1 optical transitions in addition to the bright intrinsic NC emission. Here, we use noncollinear density functional theory (DFT) to investigate the roles of surface passivation and doping on the PL emission stability of perovskite NCs. Two models are investigated: (i) a pristine NC and (ii) a NC doped with the Mn2+ ion. The noncollinear DFT includes spin–orbit coupling (SOC) between different spin states and produces spin adiabatic molecular orbit...