Vertical Integration of 2D Building Blocks for All‐2D Electronics

Abstract

Abstract2D materials are promising building blocks for novel electronic devices. It is possible that future electronic devices will be entirely made of 2D materials to fully realize their potential, due to their natural thinness, atomically flat surface/interfaces and diverse properties. In this work, three typical 2D materials, i.e., monolayer molybdenum disulfide (MoS2), hexagonal boron nitride (hBN), and few layer graphene (FLG) serving as semiconducting, dielectric, and contact/gating materials, respectively, are assembled for vertically integrated multilayer devices via the layer‐by‐layer stacking process. An individual layer of all‐2D field effect transistors (FETs) shows comprehensive device performances with parameters of ultralow off‐current ≈100 fA, ultrahigh on/off ratio approaching to 1010, ideal subthreshold swing (SS) ≈100 mV dec−1, and decent room temperature mobility up to 52 cm2 V−1 s−1, benefiting from the effective dual‐gate modulation and high contact quality. Vertically stacked multilayers of all‐2D FETs are successfully achieved with nearly multiplied on‐current density, equivalent device mobility, and persevered on/off ratio and SS of the individual layers. The vertical integration of multilayered devices with different layer functions, e.g., memory, logic and sensor, are further demonstrated. This work provides a technological base for future high‐performance integrated devices based on all‐2D materials.