In this presentation, we present our recent research advances in preparation and characterization of high quality graphene-like materials, as well as their related transistors and photodetectors. We will discuss in detail growth mechanisms of graphene and other TMD layered materials and scattering mechanisms of electronic transport on the supported layered materials. We will present several interface engineering strategies in preparing high-quality graphene-like sheets, and devising high-performance graphene-like transistors and photodetectors by reducing the electrically deleterious species at the active hetero-interface via highly-ordered self-assembled monolayers (SAMs), as well as by promoting photon-layered material interaction via hybrid layered material/photonic waveguide and heterostructure configurations.