Photoinduced Carrier Doping of α-RuCl3 through Interlayer Charge Transfer

Abstract Controlling doping density in correlated quantum materials offers a route to tuning their electronic states, but chemical doping can introduce disorder and limits dynamic control. Here, we demonstrate optically tunable electron doping of the layered Mott insulator α-RuCl3 through photoinduced interlayer charge transfer in MoS2/α-RuCl3 heterostructures. Photoluminescence and transient absorption measurements support electron transfer to α-RuCl3, leaving holes in MoS2. The layer-separated carrier population persists for more than 100 ps with an estimated doping density tunable through the excitation fluence. Selective excitation of α-RuCl3 further reveals hole transfer to MoS2. Transient absorption microscopy yields an early time effective hole diffusion coefficient of approximately 100 cm2 s–1 in the heterostructure, supporting a predominantly unbound carrier population. These results establish photoinduced charge transfer as a means of dynamically controlling carrier doping in α-RuCl3, providing a route toward optical manipulation of correlated electronic states.