Degradation of Phosphorene in Air: Understanding at Atomic Level

TL;DR

This study uses atomic-level simulations to reveal how phosphorene degrades in air, primarily through spontaneous oxygen dissociation and subsequent reactions with water, impacting its stability in electronic applications.

Contribution

It provides a detailed atomic-level understanding of phosphorene's degradation mechanisms in air, highlighting the roles of O2 and H2O interactions based on first-principles calculations.

Findings

O2 spontaneously dissociates on phosphorene at room temperature.

H2O interacts weakly with pristine phosphorene but reacts exothermically if oxidized.

Oxidation followed by water reaction is the main degradation pathway.

Abstract

Phosphorene is a promising two dimensional (2D) material with a direct band gap, high carrier mobility, and anisotropic electronic properties. Phosphorene-based electronic devices, however, are found to degrade upon exposure to air. In this paper, we provide an atomic level understanding of stability of phosphorene in terms of its interaction with O2 and H2O. The results based on density functional theory together with first principles molecular dynamics calculations show that O2 could spontaneously dissociate on phosphorene at room temperature. H2O will not strongly interact with pristine phosphorene, however, an exothermic reaction could occur if phosphorene is first oxidized. The pathway of oxidation first followed by exothermic reaction with water is the most likely route for the chemical degradation of the phosphorene-based devices in air.