Ultrafast Charge Separation in Bilayer WS2/Graphene Heterostructure Revealed by Time- and Angle-Resolved Photoemission Spectroscopy

Efficient light harvesting devices need to combine strong absorption in the visible spectral range with efficient ultrafast charge separation. These features commonly occur novel ultimately thin van der Waals heterostructures type II band alignment. Recently, separation was also observed monolayer WS 2 /graphene I Here we use time- and angle-resolved photoemission spectroscopy show that occurs at interface between bilayer graphene indicating indirect gap of does not affect transfer layer. The microscopic insights gained present study will turn out be useful for design optoelectronic devices.