The present disclosure relates to a semiconductor device and a photoelectronic device, both including a transition-metal dichalcogenide thin-film, and to a method for producing a transition-metal dichalcogenide thin-film. The transition-metal dichalcogenide thin-film includes: a first region including a stack of N+M transition-metal dichalcogenide molecular layers; and a second region including a stack of N transition-metal dichalcogenide molecular layers, wherein the second region is horizontally adjacent to the first region, wherein the N transition-metal dichalcogenide molecular layers of the second region respectively horizontally extend from the N transition-metal dichalcogenide molecular layers of the first region.