  III-nitride wide bandgap semiconductors exhibit large exciton binding
energies, preserving strong excitonic effects at room temperature. On the other
hand, semiconducting two-dimensional (2D) materials, including MoS$_2$, also
exhibit strong excitonic effects, attributed to enhanced Coulomb interactions.
This study investigates excitonic interactions between surface GaN quantum well
(QW) and 2D MoS$_2$ in van der Waals heterostructures by varying the spacing
between these two excitonic systems. Optical property investigation first
demonstrates the effective passivation of defect states at the GaN surface
through MoS$_2$ coating. Furthermore, a strong interplay is observed between
MoS$_2$ monolayers and GaN QW excitonic transitions. This highlights the
interest of the 2D material/III-nitride QW system to study near-field
interactions, such as F\"orster resonance energy transfer, which could open up
novel optoelectronic devices based on such hybrid excitonic structures.
