Abstract: A substrate including a base substrate, an interfacial bonding layer disposed on the base substrate, and a thin film adaptive crystalline layer disposed on the interfacial bonding layer. The interfacial bonding layer is solid at room temperature, and is in liquid-like form when heated to a temperature above room temperature. The interfacial bonding layer may be heated during epitaxial growth of a target material system grown on the thin film layer to provide the thin film layer with lattice flexibility to adapt to the different lattice constant of the target material system.