  Semiconducting 2D materials, such as transition metal dichalcogenides (TMDs),
are emerging in nanomechanics, optoelectronics, and thermal transport. In each
of these fields, perfect control over 2D material properties including strain,
doping, and heating is necessary, especially on the nanoscale. Here, we study
clean devices consisting of membranes of single-layer MoS2 suspended on pillar
arrays. Using Raman and photoluminescence spectroscopy, we have been able to
extract, separate and simulate the different contributions on the nanoscale and
to correlate these to the pillar array design. This control has been used to
design a periodic MoS2 mechanical membrane with a high reproducibility and to
perform optomechanical measurements on arrays of similar resonators with a
high-quality factor of 600 at ambient temperature, hence opening the way to
multi-resonator applications with 2D materials. At the same time, this study
constitutes a reference for the future development of well-controlled optical
emissions within 2D materials on periodic arrays with reproducible behavior. We
measured a strong reduction of the MoS2 band-gap induced by the strain
generated from the pillars. A transition from direct to indirect band gap was
observed in isolated tent structures made of MoS2 and pinched by a pillar. In
fully suspended devices, simulations were performed allowing both the
extraction of the thermal conductance and doping of the layer. Using the
correlation between the influences of strain and doping on the MoS2 Raman
spectrum, we have developed a simple, elegant method to extract the local
strain in suspended and non-suspended parts of a membrane. This opens the way
to experimenting with tunable coupling between light emission and vibration.
