What Is the Role of a Magnetic Mo Antisite Defect on Carrier Relaxation and Spin Dynamics in 2-D MoS₂?

Antisite defects significantly influence the dynamic properties of monolayer MoS₂, yet the carrier relaxation and spin dynamics in spin-polarized Mo antisite-defective MoS₂ remain unclear. Understanding these processes is crucial for advancing optoelectronic, spintronic, and valleytronic devices. Here, we employ first-principles calculations and ab initio nonadiabatic molecular dynamics with spin-orbit coupling (SOC) to explore carrier relaxation and spin dynamics in MoS₂ with a Mo antisite defect. This defect alters the material's magnetic properties, leading to distinct relaxation behaviors: electron relaxation is slower than hole relaxation, and charge carriers in different spin channels exhibit varied dynamics. These differences arise from variations in electron-phonon coupling, SOC strength, and phonon mode activation. Our findings provide key insights into charge and spin dynamics in MoS₂ with magnetic defects and suggest strategies to enhance the performance of next-generation optoelectronic, spintronic, and valleytronic devices.