THz conductivity and photo-induced carrier dynamics in a graphene, MoS2, graphene heterostructure

The steady state AC terahertz (THz) conductivity and photo-induced carrier dynamics in a single layer of MoS
2
sandwiched in between graphene layers have been studied using sub-200 fs THz pulses. The THz conductivity of the heterostructure resembles that of the graphene. When excited with photon energy of ~1.55 eV, it is shown that about 70% of energetic carriers generated in graphene are rapidly and efficiently transferred back and forth from graphene towards MoS
2
. A mechanism accounting for this phenomenon is proposed.