Invited: New physical coupling in nanomembranes-based artificial heterostructures

Heterostructures are fundamental building blocks for modern electronic, photonic, and optoelectronic technologies. Efforts have been made to create novel heterostructures that enable the investigation of physical coupling and the exploration of advanced device architectures. High-performance applications demand heterostructures with minimal defect density, making the realization of single-crystalline heterostructures a critical goal.

Epitaxy has traditionally been the most common method for creating high-quality single-crystalline heterostructures. However, epitaxial growth faces significant limitations, including issues related to lattice mismatch and thermal budget, which restrict the range of available heterostructures. The advent of 2D materials has introduced a transformative solution. Their van der Waals bonding nature in the out-of-plane direction and extremely low stiffness allow for easy stacking without reliance on epitaxial growth. This has led to the development of van der Waals (vdW) heterostructures. More recently, layer-transfer techniques have enabled the production of freestanding nanomembranes, a new class of materials that retain bulk properties while exhibiting extremely low stiffness. These nanomembranes can be vertically stacked to create "artificial heterostructures," circumventing challenges like lattice mismatch and thermal budget, much like 2D vdW heterostructures but with broader material versatility.

Our team is at the forefront of these innovations, specializing in the fabrication of freestanding 2D and 3D nanomembranes. We have developed pioneering methods to produce these materials, characterized by their exceptional thinness, low stiffness, and minimal internal stress. These attributes make them ideal for vertical stacking and 3D integration, enabling new opportunities to explore physical phenomena and design cutting-edge device architectures. In this presentation, I will detail the principles behind the fabrication of these nanomembranes and their immense potential in advancing heterostructure-based applications, particularly in physical coupling and device innovation.