We use ultrafast spectroscopy to resolve the interlayer charge scattering processes in heterostructures (HS) of two-dimensional materials. In a WSe2/MoSe2 HS we photogenerate intralayer excitons in MoSe2 and observe hole injection in WSe2 on the sub-picosecond timescale, leading to the formation of interlayer excitons. The temperature dependence of the build-up and decay of interlayer excitons provide insights into the coupling mechanisms. In a graphene/WS2 HS we observe ultrafast charge transfer from graphene to the semiconductor. The data are consistent with hot electron/hole transfer, whereby a tail the hot Fermi-Dirac carrier distribution in graphene tunnels through the Schottky barrier into WS2.

Date Published: 10 March 2020
PDF
Proc. SPIE 11278, Ultrafast Phenomena and Nanophotonics XXIV, 112781B (10 March 2020); doi: 10.1117/12.2544386

Published in SPIE Proceedings Vol. 11278:
Ultrafast Phenomena and Nanophotonics XXIV
Markus Betz; Abdulhakem Y. Elezzabi, Editor(s)