The rapidly growing demand for artificial intelligence (AI) hardware calls for high-performance, highly integrated electronic devices beyond conventional scaling limits. Three-dimensional (3D) heterogeneous integration offers a promising solution by vertically stacking diverse materials and functional devices. However, conventional epitaxy, while essential for producing high-quality single-crystalline thin films, relies on thick substrates that fundamentally constrain integration density and architectural flexibility.

To overcome these limitations, we develop advanced epitaxy platforms for freestanding single-crystalline membranes spanning a broad range of functional materials, including elemental and compound semiconductors, complex oxides, and emerging quantum materials. By leveraging two-dimensional (2D) interlayers, nanoscale patterning, and engineered interfacial interactions, we enable the growth and release of high-quality crystalline membranes with minimal defects. Freed from substrate-induced constraints, these membranes offer enhanced material functionalities and unprecedented flexibility for heterogeneous integration. Ultimately, our research aims to establish wafer-free 3D integration platforms for next-generation AI hardware, multifunctional electronics, and intelligent systems.