Various embodiments of a semiconductor device and related fabrication methods are disclosed. In one exemplary embodiment, the semiconductor device may include a substrate and a plurality of two-dimensional semiconductor films over the substrate, where a photogain of the two-dimensional films is above about 103 when measured at room temperature. In another exemplary embodiment, a semiconductor device may comprise a substrate comprising nanorods or nanodots and a plurality of two-dimensional films disposed on the substrate.