Topology-Scaling Identification of Layered Solids and Stable Exfoliated 2D Materials

TL;DR

This study uses a topology-scaling algorithm to identify 826 stable layered materials from the Materials Project database, many of which can potentially be exfoliated into stable 2D monolayers with low energy costs.

Contribution

Introduces a topology-scaling method to systematically identify layered materials suitable for exfoliation into 2D structures, expanding the pool of potential 2D materials.

Findings

826 stable layered materials identified

681 materials have exfoliation energies below known 2D materials

Provides structural data for future 2D material research

Abstract

The Materials Project crystal structure database has been searched for materials possessing layered motifs in their crystal structures using a topology-scaling algorithm. The algorithm identifies and measures the sizes of bonded atomic clusters in a structure's unit cell, and determines their scaling with cell size. The search yielded 826 stable layered materials, which are considered as candidates for the formation of two-dimensional monolayers via exfoliation. Density-functional theory calculates the exfoliation energy of each material and 681 monolayers are found to exhibit exfoliation energies below those of certain already-extant two-dimensional materials, indicating the possibility of exfoliating them from bulk phases. The crystal structures of these two-dimensional materials provide templates for future theoretical searches of stable two-dimensional materials. The optimized structures and other data for all 826 monolayers are provided at https://materialsweb.org .