  III-V semiconductor nanowires are considered promising building blocks for
advanced photonic devices. One of the key advantages is that the lattice
mismatch can easily be accommodated in 1D structures, resulting in superior
heteroepitaxial quality compared to thin films. However, few reports break the
limitation of using bulk crystalline materials as substrates for epitaxial
growth of high-quality photonic 1D components, making monolithic integration of
III-V components on arbitrary substrates challenging. In this work, we show
that the growth of self-catalyzed GaAsSb nanowires on graphitic substrates can
be promoted by creating step edges of monolayer thickness on kish graphite
before the growth. By further alternating the deposition sequence of the
group-III element Al and the group-V elements As and Sb, it was found that
triangular crystallites form when Al is deposited first. This indicates that
the surface binding energy between the graphitic surface and the III-V nucleus
profoundly influences the epitaxial growth of III-V materials on graphitic
surfaces. Using the optimized growth recipe with an AlAsSb buffer nuclei,
vertical [111]-oriented GaAsSb/GaAs nanowires with GaAsSb-based multiple axial
superlattices were grown on exfoliated graphite, which was attached to a (001)
AlAs/GaAs distributed Bragg reflector (DBR) using the simple Scotch tape
method. Fabry-P\'{e}rot resonance modes were observed under optical excitation
at room temperature, indicating a successful monolithic integration with
optical feedback from the DBR system. These results demonstrate the great
potential for flexible integration of high-efficiency III-V nanowire photonic
devices on arbitrary photonic platforms using a 2D material buffer layer, e.g.,
graphene, without breaking the orientation registry.
