Ultra-long carrier lifetime in neutral graphene-hBN van der Waals heterostructures under mid-infrared illumination.

ABSTRACT: Graphene/hBN heterostructures are promising active materials for devices in the THz domain, such as emitters and photodetectors based on interband transitions. Their performance requires long carrier lifetimes. However, carrier recombination processes in graphene possess sub-picosecond characteristic times for large non-equilibrium carrier densities at high energy. An additional channel has been recently demonstrated in graphene/hBN heterostructures by emission of hBN hyperbolic phonon polaritons (HPhP) with picosecond decay time. Here, we report on carrier lifetimes in graphene/hBN Zener-Klein transistors of ~30 ps for photoexcited carriers at low density and energy, using mid-infrared photoconductivity measurements. We further demonstrate the switching of carrier lifetime from ~30 ps (at

SUBMITTER: Huang P 

PROVIDER: S-EPMC7018796 | biostudies-literature | 2020 Feb

REPOSITORIES: biostudies-literature