Scalable Van der Waals Encapsulation by Inorganic Molecular Crystals

Abstract

Encapsulation is critical for devices to guarantee their stability and reliability. It becomes an even more essential requirement for devices based on 2D materials with atomic thinness and far inferior stability compared to their bulk counterparts. Here a general van der Waals (vdW) encapsulation method for 2D materials using Sb2O3 layer of inorganic molecular crystal fabricated via thermal evaporation deposition is reported. It is demonstrated that such a scalable encapsulation method not only maintains the intrinsic properties of typical air‐susceptible 2D materials due to their vdW interactions but also remarkably improves their environmental stability. Specifically, the encapsulated black phosphorus (BP) exhibits greatly enhanced structural stability of over 80 days and more sustaining‐electrical properties of 19 days, while the bare BP undergoes degradation within hours. Moreover, the encapsulation layer can be facilely removed by sublimation in vacuum without damaging the underlying materials. This scalable encapsulation method shows a promising pathway to effectively enhance the environmental stability of 2D materials, which may further boost their practical application in novel (opto)electronic devices.

Universal p-Type Doping via Lewis Acid for 2D Transition-Metal Dichalcogenides

“…We also calculated the carrier concentration by the formula n(p) = q −1 C g |V th |, 20 where q = 1.6 × 10 S3). After the encapsulation by inorganic molecular crystals Sb 2 O 3 , which have been proved to be an approach to enhance the environmental stability of 2D materials due to the particular crystal structure, 21 the p-type behavior can be kept more than 20 days.…”

2D Heterostructures for Ubiquitous Electronics and Optoelectronics: Principles, Opportunities, and Challenges

“…The transistors are operated by grounding the source and applying a drain voltage; among those, the source normally utilizes multiple low-dimensional materials such as a graphene–Si junction, metal–Si Schottky junction, or graphene–semiconductor heterojunction to offer several unique advantages (e.g., ultrathin, medium price, fabrication at room temperature, and good stability) for the design of next-generation transistors (Table ). ,,,,,,,,,,,− In recent advances, there are some typical transistor types such as the FET (Figure ), tunnel-field-effect transistor (TFET) (Figure ), high-speed transistor, HETs, vertical molecular tunneling transistor, gas-channel and ion-channel transistors, ferroelectric field-effect transistors, negative capacitance field-effect transistors (NC-FETs), and barristors (Figure ).…”

2D Oxides for Electronics and Optoelectronics

“…More importantly, compared with the MoS 2 /SiO 2 FETs, MoS 2 /Sb 2 O 3 FETs had higher mobility and on/off ratio (10 8 ). Furthermore, Zhai's group [ 144 ] also deposited Sb 2 O 3 on 2D BP and realized wafer‐scale van der Waals encapsulation of 2D materials. [ 144 ] It is well known that BP is an important 2D material with high performance, but its instability in air seriously limits its application in photoelectric and electronic.…”

“…Furthermore, Zhai's group [ 144 ] also deposited Sb 2 O 3 on 2D BP and realized wafer‐scale van der Waals encapsulation of 2D materials. [ 144 ] It is well known that BP is an important 2D material with high performance, but its instability in air seriously limits its application in photoelectric and electronic. As an inorganic molecular crystal, Sb 2 O 3 layer connects with the underlying 2D materials through vdW force due to its special structure which could avoid the structural damage to the protected materials.…”

“…i) The hole mobility of BP FETs versus ambient exposure time unencapsulated and encapsulated with Sb 2 O 3 . g-i) Reproduced with permission [144]. Copyright 2021, Wiley-VCH.…”