Light-Induced Kondo-Like Spin-Spin Interaction in 4f Doped Hybrid Perovskites Semiconductors

Tuning the spin entangled electron and hole in a light-generated exciton is a fundamentally intriguing query for quantum science. Taking the advantage of easy doping nature of semiconducting hybrid perovskite, we discover that Nd2+-doped CH3NH3PbI3 (MAPbI3) perovskite exhibits a Kondo-like exciton-spin interaction under cryogenic and photoexcitation conditions. The feedback to such interaction between excitons in perovskite and the localized spins in Nd2+ is read out as notably prolonged carrier lifetimes measured by time-resolved photoluminescence, ~10 times to that of pristine MAPbI3 without Nd2+ dopant. From a mechanistic standpoint, such extended charge separation states are the consequence of the antiparalell exchange interaction between the light-induced exciton and the localized 4f spins of the Nd2+ in the proximity, as evidenced by scanning tunneling microscopy. Importantly, this Kondo-like exciton-spin interaction can be modulated by either increasing Nd2+ doping concentration that enhances the coupling between the exciton and Nd2+ 4f spins as evidenced by elongated carrier lifetime, or by using an external magnetic field that can nullify the spin-dependent exchange interaction therein due to the unified orientations of Nd2+ spin angular momentum, thereby leading to exciton recombination at the dynamics comparable to pristine MAPbI3.