Light matter interaction in WS2 nanotube-graphene hybrid devices

We study the light matter interaction in WS2 nanotube-graphene hybrid devices. Using scanning photocurrent microscopy, we find that by engineering graphene electrodes for WS2 nanotubes we can improve the collection of photogenerated carriers. We observe inhomogeneous spatial photocurrent response with an external quantum efficiency of ∼1% at 0 V bias. We show that defects play an important role and can be utilized to enhance and tune photocarrier generation.