Wafer-Scale Strain Engineering of Ultrathin Semiconductor Crystalline Layers

The fabrication of a wafer‐scale dislocation‐free, fully relaxed single crystalline template for epitaxial growth is demonstrated. Transferring biaxially‐strained InxGa1‐xAs ultrathin films from InP substrates to a handle support results in full strain relaxation and the InxGa1‐xAs unit cell assumes its bulk value. Our realization demonstrates the ability to control the lattice parameter and energy band structure of single layer crystalline compound semiconductors in an unprecedented way.