We analyze terahertz superluminescent and laser diodes using the injection pumping in the multiple graphene-layer (GL)/van der Waals barrier layers (BLs) heterostructures. The operation of such terahertz radiation sources is associated with the interband transitions in the gapless GLs under the population inversion leading to the GL negative dynamic conductivity. These devices use the lateral injection of holes and vertical injection of electrons. Such an injection might have advantages over the lateral injection of the bipolar carriers. Due to relatively large conduction band offsets at the GL-BL interface, the population inversion at the vertical injection can be markedly hampered by the injection current heating of the two-dimensional electron-hole plasma in the GLs. We show that doping GLs and/or BLs can substantially diminish the carrier heating promoting the interband population. Numerical analysis assumed the BL material parameters of MoS2 and WSe2 and showed the feasibility of such terahertz radiation sources.
- van der Waals