Independent thickness and lateral size sorting of two-dimensional materials

二维材料厚度与片径的独立筛分

Two-dimensional(2D)materials possess unique thickness-and lateral-size-dependent properties.Many efforts have been devoted to obtaining 2D materials with narrow structure heterogeneity while it is still challenging to independently control their thickness and lateral size,limiting their widespread applications.Here,we develop a three-step method which achieves independent thickness and lateral size sorting of 2D materials.Taking 2D h-BN flakes as an example,their thickness and lateral size are independently sorted to different fractions with thicknesses smaller than 6 nm.In addition,the 2D h-BN flakes possess narrow distributions of both thickness and lateral size.We further develop a force field extraction method and achieve scalable size sorting of 2D h-BN,which is universal for sorting other 2D materials including MoS2 and graphene oxide.This work reports an effective method to produce structure homogenous 2D materials and will help fundamental studies and applications of 2D materials where thickness and lateral size are of concern.

二维材料是当前科学研究的前沿领域.二维材料的性质与其厚度和片径密切相关,如何获得厚度和片径均匀且可调控的二维材料,是其应用的关键.本文提出了一种三步筛分法,实现了二维材料厚度与片径的独立筛分.以二维六方氮化硼为例,三步筛分法可以将其厚度和片径独立地筛分为不同组分,所得组分均具有较窄的厚度和片径分布,且厚度全部小于6 nm.本文还进一步发展了一种力场提取法,实现了二维六方氮化硼、二硫化钼和氧化石墨烯的规模化片径筛分,是二维材料片径筛分的普适方法.本工作提出的筛分方法可制备出结构均一的二维材料,对其基础研究与应用意义深远.