  Confinement of monolayers into quasi-one-dimensional atomically-thin
nanoribbons could lead to novel quantum phenomena beyond those achieved in
their bulk and monolayer counterparts. However, current experimental
availability of nanoribbon species beyond graphene has been limited to
bottom-up synthesis or top-down patterning. In this study, we introduce a
versatile and direct lithography-free approach to exfoliate a variety of bulk
van der Waals (vdW) crystals into nanoribbons. Akin to the Scotch tape
exfoliation in producing monolayers, this technique provides convenient access
to a wide range of nanoribbons derived from their corresponding bulk crystals,
including MoS2, WS2, MoSe2, WSe2, MoTe2, WTe2, ReS2, and hBN. The nanoribbons
are single-crystalline, parallel-aligned, flat, and have high aspect ratio. We
demonstrated the electrical, magnetic, and optical properties from the
confinement, strain, and edge configurations of these nanoribbons. This
versatile preparation technique will pave the way for future experimental
investigation and broad applications in optoelectronic, sensing, electronic and
quantum devices.
