  Controlling excitons and their transport in two-dimensional (2D) transition
metal dichalcogenides (TMDs) heterostructures is central to advancing photonics
and electronics on-chip integration. We investigate the controlled generation
and manipulation of excitons and their complexes in monolayer (1L) MoSe2-WSe2
lateral heterostructure (LHS), directly grown via water-assisted chemical vapor
deposition. Using a field-effect transistor design by incorporating a few-layer
graphene back gate, single-layer graphene edge contact and encapsulation with
few-layer hexagonal boron nitride, we achieve precise electrical tuning of
exciton complexes and their transfer across 1D interfaces. At cryogenic
temperatures (4 K), photoluminescence and photocurrent maps reveal the
synergistic effect of local electric field and interface phenomena in the
modulation of excitons, trions, and free carriers. We observe spatial
variations in exciton and trion densities driven by exciton-trion conversion
under electrical manipulation. The first-principle density functional theory
calculation reveals significant band modification at the lateral interfaces and
graphene-TMDs contact region. Furthermore, we demonstrate the versatility of 2D
TMDS LHS in hosting and manipulating quantum emitters, achieving precise
control over narrow-band emissions through modulating carrier injection and
electrical biasing. This work extends the boundary of the present understanding
of excitonic behaviour within lateral heterojunctions, highlighting the
potential for controlled exciton manipulation across 1D interfaces and paving
the way for next-generation electro-optical quantum devices.
