Various embodiments provide a buffer layer that is grown over a silicon substrate that provides desirable device isolation for devices formed relative to III-V material device layers, such as InSb-based devices, as well as bulk thin film grown on a silicon substrate. In addition, the buffer layer can mitigate parallel conduction issues between transistor devices and the silicon substrate. In addition, the buffer layer addresses and mitigates lattice mismatches between the film relative to which the transistor is formed and the silicon substrate.