An epitaxial film should be a cutout of the material's crystal structure and MoS2 is no exception to that. If you look at the arrangement of the atoms within one layer, e.g. the top sulfur layer, they are already atom triangles. So, for mesoscopic layers, the options you have for its ends are angles of 60° and 120°, see e.g. the last figure here:

Article Controllable synthesis of MoS2 nanostructures from monolayer...

Whether it prefers 60° or 120° as a termination, can be controlled by the substrate:

Article Substrate effects on the CVD growth of MoS2 and WS2

Jürgen Weippert Why do you use chatgpt for answering questions? According to AI detector your answer is 90% chatgpt generated.

Paul Owiredu It depends on the growth mechanism. There are two main factors to consider: nucleations and partial vapor pressures of the precursors, which again depend on the temperature profile, gas flow rate, precursors and substrates arrangement, growth duration, etc.

I have found this good paper which talks about these things:

Article Shape Evolution of Monolayer MoS 2 Crystals Grown by Chemica...