Optimization of Mechanically Assembled Van Der Waals Heterostructure Based On Solution Immersion and Hot Plate Heating

Xunyong Lei

doi:10.1088/1742-6596/2152/1/012007

Abstract

Layers of two-dimensional material are bonded together by van der Waals force, as a result, there is no need to take into consideration of the lattice mismatch in the formation of heterojunction, which is endowed with the characteristics of simple stacking in method, free of limitation to the type of materials and diverse changes. However, although the Van Der Waals heterojunction is relatively easy to stack, it is still difficult to generate inter-layer coupling between the thin crystal layers that form the Van Der Waals heterojunction. In most cases, the stacked heterojunction is simply stacked together without any new effects. Therefore, the realization of heterojunction coupling is a difficult problem to be considered in the process of preparing Van Der Waals heterojunction. In this paper, a method based on solution immersion and hot plate heating is proposed to optimize the mechanical stacking of Van Der Waals heterojunctions. It is found that the heterojunctions prepared by normal mechanical stacking method are usually uncoupled before treatment, but they can be stably coupled after treatment. Our method, simple, fast with low-cost, has been repeatedly verified to have a high success rate of coupling, which is suitable for most experimental groups to use and reproduce.

Highlights

Two-dimensional materials have become a hot area of research in condensed matter physics after graphene is discovered
A method based on solution immersion and hot plate heating is proposed to optimize the mechanical stacking of Van Der Waals heterojunctions
Taking the transition metal sulfur compounds (TMDs) as an example, this paper describes double transition metal sulfur compounds heterojunction by using our preparation method, and a new interlaminar exciton emission peak and a new interlaminar Raman model have been measured in the region of heterojunction, confirming that interlayer couplings exist in heterojunction after processed .We stack different types of heterojunctions by changing the types of transition metal chalcogenides, and the interlayer coupling phenomenon can be found in all of them, which proves that our experimental method is universal

Summary

Introduction

Two-dimensional materials have become a hot area of research in condensed matter physics after graphene is discovered. Layers of two-dimensional material are bonded together by van der Waals force, as a result, there is no need to take into consideration of the lattice mismatch in the formation of heterojunction, which is endowed with the characteristics of simple stacking in method, free of limitation to the type of materials and diverse changes.

Results

Conclusion