Freestanding oxide thin films for next-generation electronics: Advances in preparation, van der Waals integration and devices

Freestanding oxide thin films represent a revolutionary platform for next-generation high-performance electronics, offering unparalleled electrical, optical, and mechanical properties. However, realizing their full potential hinges on overcoming key challenges in scalable fabrication, controlled release, and damage-free integration—particularly when interfacing with delicate two-dimensional (2D) materials or nanoarchitected devices. This review highlights cutting-edge strategies to address these barriers, with a central focus on van der Waals (vdW) integration as a transformative paradigm. Established fabrication techniques-including mechanical exfoliation, chemical vapor synthesis, remote epitaxy, and sacrificial layer-based wet-etching are critically analyzed, while persistent limitations are dissected such as strain control, interface stability, crystalline integrity, and thickness precision. The significant advantages offered by vdW integration are underscored, particularly in reducing carrier scattering, enhancing device performance, and enabling novel functionalities. Successful applications in transistors, memristors, and flexible devices are presented, demonstrating the transformative potential of freestanding oxides. Finally, future pathways are outlined for optimizing fabrication processes and developing scalable manufacturing techniques. These advancements are crucial for unlocking broader applications in disruptive technologies, ultimately positioning freestanding oxides integrated with 2D materials as pivotal hybrid material platform for future electronics.