Tuning Band-Edge Spin–Orbit Coupling to Prolong Carrier Lifetime in CsPbBr ₃ Perovskites

Experimental studies have demonstrated that doping magnetic ions into halide perovskites offers a promising route to tailor electron spin dynamics and suppress nonradiative charge recombination, yet the underlying atomistic mechanism remains elusive. Using nonadiabatic molecular dynamics simulations, we demonstrate that Mn doping in CsPbBr₃ enhances spin polarization without introducing midgap trap states compared to the pristine system. This spin polarization reduces nonadiabatic coupling between band-edge states while activating additional spin-orbit coupling (SOC)-mediated spin-flip channels within CBM↑/CBM↓ and VBM↑/VBM↓. These channels enable dynamic charge redistribution among spin-resolved orbitals, thereby prolonging carrier lifetimes. Our study reveals how band-edge SOC governs charge recombination and spin relaxation dynamics in halide perovskites, providing design principles for high-performance optoelectronic devices.