Van der Waals‐Interface‐Dominated All‐2D Electronics

Abstract

The interface is the device. As the feature size rapidly shrinks, silicon‐based electronic devices are facing multiple challenges of material performance decrease and interface quality degradation. Ultrathin 2D materials are considered as potential candidates in future electronics by their atomically flat surfaces and excellent immunity to short‐channel effects. Moreover, due to naturally terminated surfaces and weak van der Waals (vdW) interactions between layers, 2D materials can be freely stacked without the lattice matching limit to form high‐quality heterostructure interfaces with arbitrary components and twist angles. Controlled interlayer band alignment and optimized interfacial carrier behavior allow all‐2D electronics based on 2D vdW interfaces to exhibit more comprehensive functionality and better performance. Especially, achieving the same computing capacity of multiple conventional devices with small footprint all‐2D devices is considered to be the key development direction of future electronics. Herein, the unique properties of all‐2D vdW interfaces and their construction methods are systematically reviewed and the main performance contributions of different vdW interfaces in 2D electronics are summarized, respectively. Finally, the recent progress and challenges for all‐2D vdW electronics are discussed, and how to improve the compatibility of 2D material devices with silicon‐based industrial technology is pointed out as a critical challenge.

Recent progress on ambipolar 2D semiconductors in emergent reconfigurable electronics and optoelectronics

“…[164] Due to their extremely thin thickness, 2D vertical heterostructures provide a short diffusion distance for charge carriers. [165,166] In contrast to laterally stacked heterojunctions, vertically stacked heterostructures offer a larger surface area for the interface of layered materials and involve tunneling effect between the two layers, making it highly suitable for photosensitive device applications. [167] Vertical van der Waals heterostructures combined with ambipolar 2D semiconductors allow for the integration of highly disparate materials with crystal lattice mismatching.…”

Self-Powered Photodetector with High Efficiency and Polarization Sensitivity Enabled by WSe2/Ta2NiSe5/WSe2 van der Waals Dual Heterojunction

“…Given the needs of IoT application and low power dissipation, self-powered photodetectors that convert light into electric signals in the absence of external bias have ushered in research and development boom in a variety of fields like thermal imaging, surveillance, optical communication, environmental monitoring, and so forth. − Especially, 2D vdW heterostructures driven by the built-in electric field provide a degree of freedom for self-powered photodetection with on-chip integration technology, which benefit from adjustable atomic thicknesses, negligible lattice mismatching constraints, the strong layer-by-layer coupling effect, etc. − A wealth of all-2D vdW SHJ devices fabricated by the artificial stacking or vdW epitaxy techniques have been reported to realize self-powered photodetection. For example, Xin et al reported an artificial stacked GeSe/MoS 2 vdW heterojunction photodetector with a moderate EQE of 24.2% .…”

In-Depth Analysis on Self Alignment Effect of the Fermi-Level Using Graphene on Both n- and p-Type Semiconductors

“…Graphene (Gr) is a 2D semimetallic material composed of a single layer of carbon atoms. Although it is known to have a zero bandgap, in which the conduction and valence bands cross at the Dirac point, it can effectively suppress MIGS owing to the VdW contact. − Furthermore, when Gr is in contact with the metal, a charge-sharing effect occurs from Gr to the metal, which aligns the FLs on both sides of the contact. Considering these features, Gr is a qualified interlayer candidate for a universal MIS contact structure suitable for both n- and p-type semiconductors.…”