  Recent theoretical works on two-dimensional molybdenum disulfide, MoS$_2$,
with sulfur vacancies predict that the suppression of thermal transport in
MoS$_2$ by point defects is more prominent in monolayers and becomes negligible
as layer number increases. Here, we investigate experimentally the thermal
transport properties of two-dimensional molybdenum disulfide crystals with
inherent sulfur vacancies. We study the first-order temperature coefficients of
interlayer and intralayer Raman modes of MoS$_2$ crystals with different layer
numbers and stacking orders. The in-plane thermal conductivity ($\kappa$) and
total interface conductance per unit area ($ g $) across the 2D
material-substrate interface of mono-, bi- and tri-layer MoS$_2$ samples are
measured using the micro-Raman thermometry. Our results clearly demonstrate
that the thermal conductivity is significantly suppressed by sulfur vacancies
in monolayer MoS$_2$. However, this reduction in $\kappa$ becomes less evident
as the layer number increases, confirming the theoretical predictions. No
significant variation is observed in the $\kappa$ and $ g $ values of 2H and 3R
stacked bilayer MoS$_2$ samples.
