Encapsulation and Beyond Encapsulation for 2D Electronics

Two-dimensional (2D) semiconductors are widely regarded as promising candidates to overcome the scaling limitations of silicon-based technologies. Currently, research in 2D electronics has rapidly evolved from proof-of-concept single-device studies to wafer-scale fabrication, scale integration and “lab to fab” transition. Challenges related to stability and variability remain critical hurdles. Among various strategies, encapsulation has emerged as the most effective method to preserve device performance and shield against environmental degradation. However, encapsulation technology has received comparatively less attention than other aspects of 2D electronics. In this review, a comprehensive and forward-looking analysis of the encapsulation landscape for 2D electronics is presented. It is begin by examining the molecular-level degradation mechanisms of representative 2D materials, and then systematically summarize and categorize current mainstream encapsulation approaches into in-situ growth (both high- and low-energy routes), in-situ oxidation, and van der Waals (vdW) encapsulation. To address future integration challenges, the concept of “Encapsulation by Design” is introduced, advocating for the development of tailored encapsulation schemes aligned with specific device functions and scalable manufacturing requirements. Further, a concept of “Beyond Encapsulation” is proposed, which redefines encapsulation not merely as a protective layer but as a multifunctional platform capable of enhancing and expanding the capabilities of 2D devices. Within this framework, it is outlined three emerging directions: 1) Encapsulation for material functionalization; 2) Encapsulation for further vdW technologies; 3) Encapsulation for monolithic 3D integration, which can encourage broader awareness of the multifunctional and transformative roles encapsulation can play in 2D field.