Fig. 2: Device fabrication and basic electrical characteristics.
From: Self-driven WSe2 photodetectors enabled with asymmetrical van der Waals contact interfaces
a Optical picture of one fabricated graphene–WSe2–Au structure by the dry-transfer process. The red dashed lines indicate the boundary of the van der Waals contacts. Scale bar 30 μm. b Raman spectrum obtained on the multilayer graphene–WSe2 contact region. For the lower Raman shift range, the laser power is increased to five times to identify the WSe2 characteristics. The excitation wavelength is 532 nm. c Atomic force microscope image of the fabricated graphene–WSe2–Au structure. d Height profile of the graphene–WSe2 heterostructure along the red dashed line in c. e Transfer curves and f output curves of the fabricated graphene–WSe2–Au structure.
