Theoretical prediction of sandwiched two-dimensional phosphide binary compounds sheets with tunable bandgaps and anisotropic physical properties

TL;DR

This study predicts new stable 2D GaP and InP monolayers with tunable bandgaps and anisotropic properties, offering potential for advanced electronic and optoelectronic applications.

Contribution

It introduces novel 2D GaP and InP allotropes with unique structures and tunable electronic properties, expanding the understanding of 2D phosphide materials.

Findings

Predicted stable 2D GaP and InP monolayers with high buckled orthorhombic lattices.

Band gaps are significantly wider than bulk counterparts and tunable by strain.

Potential synthesis pathways for these 2D phosphide compounds are proposed.

Abstract

New allotropes of two-dimensional (2D) GaP and InP binary compounds were predicted from the structural optimization and dynamical stability analysis in the framework of the density functional calculations. These stabilized GaP and InP monolayers possess unique high buckled orthorhombic lattices symmetry with their cohesive energies of ~0.14 and ~0.17 eV/pair lower than those of 2D low buckled honeycomb GaP and InP binary compounds, demonstrating that these newly predicted 2D GaP and InP binary compounds are energetically preferential. More interesting, their energy band gaps are even ~ 0.52 eV (for GaP) and ~1.49 eV (for InP) wider than their bulk counterparts. Such band gaps are also tunable under the strain along armchair/zigzag direction, and the direct/indirect band gap transitions occur under certain strain, providing their promising applications in band gap engineering for nanoscale electronic and optoelectronic devices. A feasible way to synthesize these novel 2D phosphide compounds is also provided in this study.