Substrate Induced van der Waals Force Effect on the Stability of Violet Phosphorous

TL;DR

This study combines experimental and theoretical approaches to show how substrate-induced van der Waals forces critically affect the stability and environmental interactions of violet phosphorus, a wide band gap vdW semiconductor.

Contribution

It provides new insights into how substrate properties influence vdWs forces and stability of violet phosphorus, guiding substrate selection for vdW material applications.

Findings

vdWs forces significantly impact VP stability and interactions

substrate hydrophobicity and roughness modify vdWs forces

interface forces can alter physical properties of vdWs materials

Abstract

The van der Waals (vdWs) forces between monolayers has been a unique distinguishing feature of exfoliable materials since the first isolation of graphene. However, the vdWs interaction of exfoliable materials with their substrates and how this interface force influences their interaction with the environment is yet to be well understood.Here, we experimentally and theoretically unravel the role of vdWs forces between the recently rediscovered wide band gap p-type vdW semiconductor violet phosphorus (VP), with various substrates (including, SiO$_2$, mica, Si, Au) and quantify how VP stability in air and its interaction with its surroundings is influenced by the interface force.Using a combination of infrared nanoimaging and theoretical modeling we find the vdWs force at the interface to be a main factor that influences how VP interacts with its surroundings.In addition, the hydrophobicity of the substrate and the substrate surface roughness modify the vdWs force there by influencing VP stability. Our results could guide in the selection of substrates when vdW materials are prepared and more generally highlight the key role of interface force effects that could significantly alter physical properties of vdWs materials.